Thursday, February 21, 2019

The Argus Hat

I designed a hat!

Eons ago, Hera, the queen of the gods, had a trusted guard - the giant Argus with one hundred eyes.  Argus was an exceptional guard - he never closed more than half his eyes, even when he was sleeping.  Hera asked Argus to guard Io, a young mortal woman being pursued by Hera’s husband, Zeus.  

Zeus sent his son, Hermes, to free Io from Argus and Hera.  But Argus’s peculiar sleeping habits and his many eyes proved a difficult problem. Finally, Hermes simply told a story so long and so boring that eventually all of Argus’s eyes closed in sleep. Hermes seized the opportunity and killed Hera’s trusted servant.  

To commemorate her faithful servant, Hera preserved his eyes in the tail of her favorite bird - a peacock.

Even today, Argus is synonymous with watchfulness and a guardian spirit. J.K Rowling even gave his name to one of the characters in her Harry Potter series: Argus Filch, the caretaker of Hogwarts school, who always seemed to know when students were out of their beds at night.

This hat is the first of a series of free-form hats that I designed that use short rows to concentrate colors and form “eyes.”  It is designed for variegated yarn and helps to tame the chaos that variegated yarns produce.  You will respond to the colors in the yarn and learn how to control where the eyes fall.  This hat is also a helix knit, alternating 2 strands of yarn to form an unbroken, jog-free garter stitch spiral. 

The hat itself is a reasonably simple pattern, but the short rows in response to color changes, and helix knitting make it a more challenging knit, suitable for adventurous knitters who enjoy making decisions on the fly and are comfortable with a bit of chaos.

Freeform knitting is extraordinarily difficult to explain because it's conceptually pretty different than standard knitting, and the pattern includes detailed instructions on how to control where the eyes fall.  As a result - the pattern is 14 pages long!

Here's the hat being modeled by my daughter:

The hat is available for sale in my Ravelry store.   It provides instructions for one adult size, and is designed for worsted-weight yarn, but adjusting the size (or converting for use with other yarn weights) isn't hard to do. To save space in the pattern itself (which is already pretty long), I include the instructions for adjusting the size/yarn weight here on my blog.  You can use the instructions to change yarn weights, make a fitted hat (instead of a slouchy one), or make a new size (baby, child, teen, or for someone with an extra-large noggin). 

Here's the pattern page on Ravelry. You can purchase it there, or by clicking on this link if you prefer: buy now.

Custom Fitting the Argus Hat

Adjusting the number of CO stitches or the circumference of the hat

I designed the Argus Hat for an averaged-sized adult head, which is around 22 or 23”/56-58.5cm, and if you are using worsted-weight yarn, you should cast on 96 stitches (or 88 if you like it a bit tighter).  But what if you want to use a different weight yarn (fingering, sport, DK, and aran/bulky are all possible), or what if you want to custom-fit the hat to someone with a bigger head (like for my husband who has a 24" noggin) or a child?

If using a yarn weigh other than worsted, you will need to get a nice firm fabric (but not as tight/dense as you'd try to get with socks) with your SMALLER needles.  This is the stitch gauge that you will use for the cast on.

If you are using a weight other than worsted, or if you want to custom-fit the hat, use the following table:

(Head circumference - negative ease) = hat circumference.
Hat circumference x stitch gauge = CO number.  Adjust up or down to the nearest number divisible by 8.
Head circumference

Negative ease*
Minus 4” or 7.6cm
Hat circumference
Stitch gauge per
1 inch or centimeter
CO Base
CO Actual: Adjust up/down to nearest number divisible by 8:

* Note: Negative ease means that the item is smaller around than the item being covered, so that the knitted item must stretch to fit.  Things like hat bands, cuffs and waist bands on sweaters, and the tops of socks are typically made with negative ease.  Conversely, positive ease means it's bigger around than the body part, and fits loosely. And zero ease means that it fits exactly without being loose, or having to stretch.

Adjusting the HEIGHT of the hat:

As designed, the hat is a slouchy hat. If you want a fitted beanie, not a slouchy hat, OR if you want change the size (a child-sized hat won't need to be as tall as an adult hat), then you'll use the table below.

To fit anyone regardless of size or age, measure from eyebrows over the top of the head to the base of the skull, and divide in half.  If fully covering the ears is a priority, then measure from the bottom of one earlobe, over the top of the head, to the base of the other earlobe, and then divide THAT measurement in half.  This is the height of a fitted hat from the bottom of the cuff to the top of the crown.

But ... the hat height = cuff+rise+crown decreases.   So, in order to make a fitted hat, you need to figure out how tall the crown decrease section is, and subtract that from the total, and that's how tall you make the hat, before starting the decreases.

Figuring out the height of the crown decrease section can be tricky.  Basically, you have to figure out exactly how many rounds are in the crown decrease section (counting both decrease rounds AND the rounds between them, as for this hat you decrease every other round).  I usually have to work it in a spreadsheet.  But, for the Argus Hat, I've done the work for you. :-)

Just plug in your values into the table, and do the math, and it will give you your hat height.

So, to fit the hat height, do one of the measurements described above, and determine your ROW gauge.  If you are making an adult hat, knit until the hat is right about 4" (10 cm) tall from the cast on edge and then determine your row gauge. Row gauge in this hat is tricky, because the number of rounds varies due to the short rows.  So, take several measurements, and average them.

If you are making a child's hat, determine your row gauge when it's about 3" (7.5 cm) tall from the cast on edge, and if making a baby hat, determine your row gauge when it's about 2" (5 cm) tall.

Sample hat
Your hat


Number of CO stitches

Divided by number of decreases per decrease round

Subtract 4
(because you only decrease until 32 sts remain). This is the number of regular decrease rounds.

Multiply by 2 (because  you are only decreasing every OTHER round)

Add one (because there’s an additional k2tog all the way around). This is the number of rounds in crown.

Determine your ROW gauge (per 4”/10cm)

Convert to rounds per 1”/1 cm

Divide number of rounds in crown by row gauge per 1 inch/cm. This is the height of the crown.
7 cm

Eyebrow-to-base of skull measurement divided in half:
19 cm

Subtract crown height from measurement above.
12 cm

Add additional height for slouch (optional).
0 cm

Knit to this height before starting the crown decreases.
12 cm

Here's the pattern page on Ravelry. You can purchase it there, or by clicking on this link if you prefer: buy now.

Saturday, February 2, 2019

Periodicity 3.4: Common Effects - Richer Color

Sometimes though, what you get when knitting with a variegated skein, is a fully-mixed fabric with a depth of color that you didn’t expect.  These little gifts-of-the-gods can be very hard to predict, though.  I THINK they occur most often when the colors in the skein are very close to each other.

Fully-mixed fabric that really works for me, happens because the skein contained colors that are very close on the color wheel, and of similar tones, and intensities, so that then they are mixed, create a unified, rich color (Example: blue and green, that appears blue-green from a distance, and kind of flickery up close).

Or perhaps the skein is all one color, but different intensities.  Here's an example of that in my "Ravelry Red" Malabrigo sweater:
© Cathy Byland Weeks

... Or the light orange section of my brother's Jayne Cobb hat:
© Cathy Byland Weeks

Like all things, this is a subjective thing. If it looks good to you, go with it.

Back to TOC. Back to Effects Intro.

Periodicity 3.3: Common Effects - Color Confetti (AKA fully-mixed fabric)

Color Confetti (aka fully-mixed fabric)
As with pooling, when the gauge, number of stitches across/around interacts just right (or wrong!) with a yarn's skein length and color repeat length, it produces a fabric where the colors are evenly mixed, with no pooling or flashing. The color is often flickery, and reminds me of confetti or sprinkles of color.  My Ravelry friend Nathalie/Skeincharmer calls it buckwheat: "Each grain is different shade of brown but together they produce a uniform, cohesive look."

Used under a Creative Commons BY-SA 3.0 license.
Originally, I called this kind/sort of fabric "muddy," but a funny thing happened on the way to this article - one person's "muddy" was the next person's "rich and cohesive."  Over and over again, I saw examples on Ravelry, of projects the knitter who produced it called ugly, that I thought was gorgeous (and occasionally, it happened in the opposite direction).  And, as my Ravelry friend Jaya/Ermabom reminded me, mud-dyed fabrics and yarns are often rich, varying, gorgeous and highly underrated.  And another Ravelry friend Carole/Koiguki sent me a couple of videos on Japanese silk dying that uses mud to create a deep, rich, intensely dark fabric (here's one if you're interested).

So, I decided to call it “Color-Confetti”, because that’s what it most reminds me of - i.e. flickery mixtures of fully mixed color combinations with no apparent pooling.   They actually remind me a little of random-dot stereograms (but without the 3D part):

Random dot stereogram depicting a shark. Used under a Creative Commons BY-SA 3.0 license

In my highly judgmental and utterly subjective opinion, I generally prefer pooled fabrics to color-confetti fabrics (although, there are always plenty of exceptions). The lovely colors in the skein sometimes seem to get lost in the “noise” when the colors are fully mixed.

However, there are always exceptions. Here are some exceptions that I think are gorgeous:

Used with permission. ©Susi/SusiJB 


Used with permission. ©Kris/Kristoemily


Used with permission. © Jenny Sanders

I've been trying to figure out why - even though I prefer pooled fabrics - I like the above examples. I think it's because the colors are bold enough to not get lost, or the melange of color just "works," which I know is not terribly helpful.

Back to TOC. Back to Effects Intro. Forward to Richer Color.

Periodicity 3.2 Common Effects - Inconsistent Results

Another common effect, is that the fabric produced is inconsistent. It may produce inconsistencies in the same garment when you change skeins, between matching items (one sock patterns differently than the other), and when changing stitch counts in the same garment.

You might not mind the flashing so much, but then it stops, and looks completely different in another spot.  Or it's mixed nicely, then you start a new ball of yarn, then it flashes horribly.  Or it’s mixed nicely but you decrease or increase because you are creating covering for a three-dimensional shape, and BOOM, it starts striping. It's also very common for each sock in a pair to pool differently.

Example: Inconsistency caused by changes in gauge or stitch count
Pooling be caused (or broken) by changes made by the knitter - changing the gauge/needle size, or the stitch count (You see this in sweaters and hats - where the width of the fabric changes, the patterning does too).

Here's a planned pooling hat that I made - I was delighted with the pooling/flashing in the hat rise, but when I began the crown decreases, I was NOT amused.  I ended up frogging back to where I started the decreases, and did a completely different crown that allowed me to keep the stitch count consistent.  Eventually I'll release this pattern (once I figure out a different cuff).

© Cathy Byland Weeks
You will see similar effects in sweaters, in response to shaping to fit the contours of a torso.

Example: Inconsistencies caused by changing skeins of yarn.

Inconsistencies are also caused when you start a new skein - the colors are slightly different, and pool slightly differently. This is most common when using hand-dyed yarns. No two skeins are the same, even among skeins within the same colorway.  This can be sometimes be mitigated by starting the new skein at the same spot in the color-repeat sequence, but that's not a certain fix.  Note Natalia/Skeincharmer's sweater below - the blue arrows show where each new skein was started.

Used with permission. © Natalia Vasilieva/Skeincharmer

One skein of my Ravelry Red sweater was a little lighter than the others. You can the light streak going across it, a couple of inches below the top:
© Cathy Byland Weeks

Sometimes however, the inconsistency when changing skeins was caused by something beyond the knitter's control. In the case below, the knitter used a very consistent, machine-made yarn, but the final skein was wound in the opposite direction to the previous ones.   Note the direction of the stripes and spirals in the hem:

Used with permission. © Nicole/Grudgemom

Example: Inconsistencies between matching garments

It's even possible for matching garments (like two socks in a pair) will look different, even when they are made from the same skein of yarn.
Used with permission. © Rebecca/itgirl

I don't know what caused Rebecca's socks to turn out so differently from each other, but it can be caused by several different factors:  
  • Knitting from both ends of the cake: If a knitter knits socks 2AAT, and knits from both ends of a single cake, the socks are going to turn out really differently, because the colors are going in opposite directions. 
  • Starting each sock at different points of the skein color sequence.  
  • Knitting the two items with slight (or extreme!) differences in gauge. This can happen even when the knitter used the same needles and stitch counts.
  • Differences within the skein itself - the first half of the ball may have different color-lengths than the second ball. 
  • Check your stitch counts. Yarn Harlot wrote about her socks being different because she knit one sock as a medium, and the second one as a small.
Back to TOC. Back to Effects Intro. Forward to Color Confetti

Periodicity 3.1: Common Effects - Pooling and Flashing

Pooling and Flashing
Probably the best-known effect of working with variegated yarns is pooling, and its crazier sibling, flashing.  It is the opposite of a well-mixed fabric.

Simply stated, pooling is where the individual colors wind up near each other in the fabric, creating “pools” or patches of the same color.   Pooling is the result of your stitch count and gauge being just right (or wrong depending on your opinion on the subject).

Pools can be big or small.  Here's a rather loud headscarf with small pools:

@ Cathy Byland Weeks

Pooling isn't always loud. It can be quite sedate, with bigger pools of color. Here's a hat I made for a friend. Note that the yarn was dark green, with the big light green sections. You can see the lighter green streaks.
© Cathy Byland Weeks
Argyles are a special kind of offset pooling, when knitting flat (knitting back-and-forth causes the colors to zig-zag up the piece, bouncing off the sides):
© Cathy Byland Weeks
Offset pooling in the round makes spirals.  I think it may be impossible to make argyles while knitting in the round, though I'm not sure of that.  I've come up with schemes similar to intarsia in the round that might work, or knitting hats sideways and then grafting them.  But that'll take some more work and experimentation.

Flashing is a type of pooling where the pools make lighting bolts or zig-zags.  This effect is most common in items made in hand-dyed yarns, which typically have inconsistent color-lengths.

© Cathy Byland Weeks

© Cathy Byland Weeks
The flashing in the socks and headscarf (above) wasn't planned, but I pooled the following hat deliberately (though the flashing wasn't deliberate, just a happy result). It's a tam that is knit at 2x my magic number:

© Cathy Byland Weeks

There are other kinds of pooling as well, which will be covered later.

One term you’ll see associated with pooling (or more specifically, planned pooling projects), is “magic number.” The magic number is the number of stitches at a specific gauge, that are taken up by one color repeat, or one loop of the hank.   Knowing the magic number allows you to use the pooling to deliberately create stacked pools or argyles.  But, more on that later.

For those that want to read ahead with magic number info (it is super-cool, and really intriguing), here are some pages I liked:

Back to TOC. Back to Effects Intro. Forward to Inconsistent Results.

Periodicity 3: Common Effects Intro

Images on left: © Cathy Byland Weeks.  Top Right: © Nathalie/Skeincharmer. Bottom Right: ©Susi/SusiJB.

One thing you can always count on with variegated  yarns; working with them is never boring. Disappointing, surprising, sometimes lovely, sometimes ugly, but boring it is not.

They have a tendency to surprise us, especially when we give in to our impulses and bring home that multi-colored skein of goodness, wind it into a cake and start knitting with it.  Some yarnies have a high tolerance for chaos and enjoy the often surprising effects. And others will find themselves dissatisfied.

And really, mitigating that dissatisfaction is the main point of this series.  The other point is for the ones who enjoy the chaos and winging it and just seeing what you get (and have a low tolerance for testing) by the end, if you are still with me, you'll at least understand why things turn out the way they do.

There are several common results when working with variegated yarns:
It is probably not surprising that knitters often seem to either love or hate the above effects, particularly pooling/flashing and color confetti. But even then, there are always exceptions. I can't tell you how many times I see stuff like, "I normally hate pooling but that is just ... cool."  Or, "Variegateds always turn to color-mush when I use them, but that fully-mixed fabric is kind of ... flickery and lovely."

So, I guess what I'm telling you, is that every project I show as an example - you may not like it. And that's okay.  Just remember that there could well be other examples you probably WILL like.

Back to TOC.

Knitting is some dark magic

The swatch knitted from VHS tape (yes, he still has it)

Years ago, when I was a beginning knitter, I looked down at my little square of knitting, and felt … wonder and awe that I’d created this fabric out of interlocking loops. Chris and I were sitting together watching TV, and I said, “This is … magical.” He looked at my little square and said, “…. Ok.” (obviously not getting it).

Early on, Chris kept asking me to knit him little samples of really weird fibers. I’ve knitted jute, sisal, VHS tape (never, never again. It squeaks something awful), even some flexible wire (never, never again. It’s murder on your hands). I finally just said, “why don’t I just teach you how to knit?” and he shrugged and said, “Ok.”

So, I taught him. I had to learn to back off though - he refused to let me teach him when I thought he was ready, and made me wait and only teach him new techniques when he wanted them. I think he made a LOT of garter stitch items before he finally let me teach him to purl. And then he was off and running. He continued experimenting with unusual materials, even going so far as creating over-sized knitting needles so he could knit rugs from strips of old jeans.  At some point, he saw a TED talk about making hyperbolic sea creatures in crochet, and he decided it could be done with knitting, dammit. He even had me make him a special 6 foot interchangeable cord so he could make bigger ones (and binding off took him foreeeeeever). Then he was fascinated with entrelac - that was the first technique he picked up on his own as I didn’t know how to do it (and still don’t). He wanted me to learn it so I could teach it to him.  I bought him an entrelac book instead.

Anyway, years and years after I’d said it, he sat gazing at his knitting for awhile, then looked up, and said, “you’re right. This is magical.”

Saturday, January 26, 2019

Hats, photos, and my address book

So, I've made a LOT of hats.  About 70 of them, if you count the headscarves. 

One thing that I do, is ask that if I give someone a hat, that I get a photo of the person, in the hat that I made for them, for my Ravelry project photos.  Fortunately, my family is happy to oblige. :-)

What I also do, is use that photo of them in my contacts/address book, so that when they call me, I see them wearing my hat on my phone screen. Like this:

That is my husband, modeling his Jayne Cobb hat (Firefly fans will know what I'm talking about) and he's is scowling in an entirely Jayne-appropriate manner.

Here are a few others:

The one exception is the picture of me (in the upper right).  I didn't make that hat. Chris did (though I felted it).

My granddaughter is too young for her own contact entry, but if she were, I'd use this photo (because she's a cutie, and this is my favorite photo of her that I've taken):

Saturday, January 19, 2019

Periodicity 12: Appendix D - Featured Project Index

Here's an alphabetized list of featured variegation projects that I referenced in articles, or featured in stand-alone articles, not including my own.  I link to the Ravelry project page, or if there is no project associated with the image, I link to the yarnie's profile page.  Check back regularly to see additions

AJ's Prismatic Scarf
Jenny/JennyXan's Electricity
Nicole/Grudgemom's Little Miss Myra's Sweater
Kris/Kristoemily's Wingspan
Rebecca/itgirl's Pool-y Mom Socks
Nathalie/Skeincharmer's Brown-and-Cream Sweater
Susi/SusiJB's Boden

Featured Variegation Project - AJ's Prismatic Scarf

Used with permission. © AJ/amewsing
Here's some serendipity: AJ did no planning at all; she just cast on and started knitting, hoping it would work out.  And, it did, in a wonderfully magical manner. Her gauge, row length, and the color repeats in the yarn itself interacted in a lovely way.

Used with permission. © AJ/amewsing

... I just cast on and starting knitting, hoping that something interesting would happen. The ribbed edging where it went all rainbow-y on its own is my favorite part. I’m probably addicted to variegated yarns. Just a bit.
Finding the best blank canvas for variegated yarn involves making sure you pick a project that’s plain enough that the yarn can do most of the work for you. Fancy stitch patterns will get lost. The neat thing is, even with mindless, simple knitting, the wildness of the yarn will keep the project from being too boring, at least in my experience. The pattern I used for my Prismatic scarf was a great choice in that it’s got some uncomplicated lace in there to balance out the simpler parts of the pattern. Really loved making it! Lonnnnng rows, though.
Also, if you’re making something and you’re getting pooling that isn’t quite what you are after, changing your gauge can make a huge difference (but sometimes you’ll need to find another pattern entirely).
For more photos, see AJ's project:
The pattern can be found here:

Here's the skein before she knitted it up:
Used with permission. © AJ/amewsing

PomPom Magic - Part II: Going Dotty and Losing Your Marbles

This is part II of my pompom series. Part I (stripes) is here.

Polka-dots are far easier to understand than stripes, but also much more fiddly, but the results can be pretty spectacular.

Pom-pom maker (I like the Clover ones, and have them in ever size they offer), but a cardboard doughnut will work. Yarn in two colors, scissors.

Basic advice for both Dotty and Marbled:
Do NOT cut the yarns while wrapping alternating colors, or even when changing layers.  This is so important it bears repeating:  Do not cut your yarns until you are ready to cut the entire pompom.

Yes, the sections will be connected, and that connection strand will be covered by future layers, but that's OK. That strand will be cut and trimmed away when you cut the pompom. Believe me, it will save you a lot of headaches, while you try and hold your short color sections in place while you get them covered by the next layer.

How many wraps for the dots?
As with stripe thickness, this will take some trial-and-error, and it depends on how big you want the dots to be.  More wraps will make bigger dots, but you'll wind up with fewer of them.
subsequent layer will "fill in" at the sides.

Can I use more than two colors?
Sure! I would recommend keeping the background color the same though.  Or not. It's totally possible to combine stripes and dots. 

Going dotty:
Polka-dotted pompoms are made in layers (as with stripes), but the main difference is that you alternate dot layers with solid layers, and you do them longitudinally, wrapping all the way across the arc.
  1. Solid background layer - wrap all the way across the arc, with a thin layer (maybe two strands deep)
  2. Dot layer: Create a dot at one side of the arc, maybe 5 or so wraps in a clump. Then leave a gap, and create another, then another, for a total of 4 or 5.
  3. Solid background layer - wrap all the way across the arc, covering the small dot sections with a thin layer (maybe two strands deep), and filling in between them, to create an even-looking arc.
  4. If making a really large pompom, you might repeat 3 and 4 once or perhaps twice  If you do, off-set the dots from their position on the previous dot layer (see 2nd and 4th images below).
  5. Repeat 1-4 for the opposite side.

Losing your marbles:
This was an attempt to create a checkerboard, but it didn't work at all, but I liked how it looked anyway.  It's also created longitudinally (wrapping all the way across).
  1. Create a layer by alternating 5 wraps of each color. So, 5 wraps of one color, then 5 wraps of the other, all the way across.  DO NOT CUT.
  2. Come back the way you came, repeating step one, but offsetting the colors.  So, cover the MC with the CC, and vice-versa. After the first layer, I tended to do all one color  then the other (guessing a little where to start and stop), but you can continue to alternate as you go, if you prefer.
  3. Repeat 1 and 2 as needed.
  4. On the other half, ensure you do the same number of layers as with the first half.  And, ensure you do it in the opposite order.  So, if you started with the MC, then start with the CC this time. 

Recommended Tools:
Here are my favorites.   If someone has the self-control to only get one size, I'd advise getting the "large" set (65 and 85 mm; the middle image, below).  I use the 65 mm by far the most.


Clover also makes an extra-small set, with 20 and 25mm diameters (.75" and 1").

PomPom Magic - Part I: Stripes

Photo  © Cathy Weeks

When I was designing my BB-8 hat (which is STILL not ready for publication), I figured out how to do some pretty cool things with pompoms.  Like create stripes and layers, and even polka-dots.

It's surprisingly easy to do, but also kind of unintuitive, in part because it feels like you are doing it out of order.  Here's the trick:  You work from the top down for the first half, then from the bottom up, for the second half.  But .... I'm getting ahead of myself. 

Pom-pom maker (I like the Clover ones, and have them in ever size they offer), but a cardboard doughnut will work. Yarn in several colors, scissors.

Making Pompoms:
I'm assuming you know how to make them already.  If you don't, check out the pages below, and then make a couple of pompoms out of scrap yarn for practice.

Making stripes - A Tale of Two Methods:
There are two basic ways to create stripes - and this is going to sound rather like a geography class.  You can make stripes along the lines of longitude (easier to make, but harder to control), or you can make stripes along the lines of latitude (confusing, but much easier to control things like stripe thickness).

Ok, the thing to remember is that the strands closest to the ties go around the "equator" and the strands farthest away from the ties form the "poles".   What that means is that the yarn color you wind first will become the pole, and you cover it up with yarn that becomes the equator.   You also need to account for the number of stripes - even numbers are easier to work with.  Half the yarn colors go on each half of the maker.  If you are using an odd number, finish each half with a thinner layer of the same color (it will form the middle stripe - the "tropics" as it were).

When you wrap, you will put your first layer down just in the center of the arc.  Then you cover that with the next layer, and fill in a little bit on either side (not shown is the green layer). Like this:

Photo © Cathy Weeks

Here's a pretty ugly hand-drawn diagram that may also help:
Top: the green would fully cover the red, and the blue would
cover the green.

Now, it's hard to represent colors that are in layers.  But in the top image of the diagram, the red would be fully covered by the green, and the green would be fully covered by the blue. 

Now, here's the hard part: When doing the first half, you work top down. When doing the second half you work bottom up. Now, this only matters, if you care about the stripe order. If the order doesn't matter, then just have some fun (and just remember to end both halves with a thinner stripe of the same color, if you have an odd number). If the order does matter, here's a guide for you, using rainbow order (Red-Orange-Yellow-Green-Indigo-Violet):

Color orderThree StripesFour StripesFive StripesSix StripesSeven Stripes
Top half
2Orange (thin)OrangeOrangeOrangeOrange
3Yellow (thin)YellowYellow
4Green (thin)
Bottom half
2Orange (thin)YellowGreenBlueIndigo
3Yellow (thin)GreenBlue
4Green (thin)

How thick do you make the stripes?
This will take some trial-and-error.   When I designed my BB-8 hat, I actually counted the wraps for several different sizes. But for this, just have some fun and be creative.   There are a few rules-of-thumb to remember, though:

  • The "south pole" has a tendency to be hidden, as it is squished against the top of the hat. Make the first color on what will be the bottom half a little thicker to compensate.  
  • If aiming for equal thickness stripes and using an odd number, make the middle band (ie, the last color on each half) thinner, about half the thickness of the other stripes.  The two halves will come together and make a normal-width stripe. 
  • If aiming for a wider middle band, and using an odd number, then make the last stripe on each half the same thickness as the others.

In a fit of over-enthusiasm, I made a TWELVE-color pompom, six colors on each side:

To make longitudinal stripes, wrap an even layer all the way across the arc, and each color will cover the one below.  With these stripes you need to make the stripes in each half about the same thickness, and in the same order, otherwise the stripes will not match up along the meridians.   So, if you want a 4-color rainbow, wrap each layer all the way across, red, yellow, green, blue. Then flip the maker around, and red, yellow, green blue again.

Can you combine methods?  Yes!  Here's an example:

Top: Latitude. Lower Left: Longitude. Lower Right: Shows how they interact
(left side shows the green longitude, meeting the yellow latitude equator on the right).

Other tips and tricks:

  • If you are repeating the yarn color, either in the same half, or in the other  half, don't cut it. Just drag the tail along.  These tails will get cut later, and trimmed to the right length.  Believe me, this is MUCH less of a headache (especially if you're doing a polka-dotted one - more on that later).  Only cut the yarn if you are actually done with it.
  • If you tie it in the wrong place, no matter. Just thread your yarn tails onto a darning needle, stab it into the center of the pom-pom and bring it out where you want it.  

Recommended Tools:
I've made pompoms from cardboard doughnuts, forks, even my hand. I've gotten good results from all of them, but I think the best results come from the cardboard doughnuts and the plastic makers.  And for convenience and ease of wrapping the yarn, nothing beats the plastic makers.  Besides, I'm a total gadget-whore.

As for size, I have all of them.  But, if someone is getting just one, I'd advise getting the "large" set (65 and 85 mm; the middle image, below).  I use the 65 mm by far the most.  The biggest one is a blast, but it makes a pom-pom roughly the size of a newborn's head, and takes about 75 grams of yarn all by itself. If you are planning a hat with that one, you'll need an extra skein of yarn.

Clover also makes an extra-small set, with 20 and 25mm diameters (.75" and 1").

Ready for some polka-dots?  See Part II of my pompom series.