While participating in an open KAL hosted by the facebook group "
Die Drei vom Blog  Knitalong", I designed a few new hats. This is the 3rd one I knitted ... but the first that has its pattern written down :) It is knitted flat from side to side and completely
without short rows.
It starts similar to the
UTurn Mitts or the
UTurn Slippers. has semicircular increases to shape the dome over your head, decreases for the slope on the other side and is finished with a threeneedle bindoff. Because of its unique construction, it's great to show off your variegated or selfstriping yarn.
The pattern contains one stitchbystitch version for exactly the same size that I knitted, an explanation on how to adapt it to a different sizes or different weights of yarn, and a generic version of the pattern.
This work by
Knitting and so on is licensed under a
Creative Commons AttributionNonCommercialShareAlike 4.0 International License.
Materials
 about 50 grams of fingering weight yarn
 3.25mm needles  I used circulars with an 80 cm cord
 three stitch markers
 a third knitting needle for the three needle BO
 a tapestry needle to weave in ends
Techniques & Notation
 Judy's Magic CastOn is a technique that gives you live stitches on both sides of your needle  it is generally used for toeup socks (e.g. in this pattern), but it can be used for other purposes as well. Here's a written description (from Knitty) and here's a YouTubevideo by Cat Bordhi and another YouTubevideo by Very Pink Knits.
 ThreeNeedle BindOff: https://youtu.be/Ph93jWSzTa0
 Knitting a flat circle  or in case of this pattern a semicircle: The technique for knitting a flat circle has been described a few times on this blog, e.g. in the "Zoom Out Mitts"Post. Basically it consists of doing 8 increases (evenly spaced out in one round) every other row, and varying the starting point for the first increase to avoid an octagon pattern.
In this pattern only a semicircle is knitted. This means that there will be only 4 increases on every RS row  and they will be started at a random stitch within the first quarter of the half circle.
As an increase I used kfb and as decrease I used ssk, but you can use other stitches as well, e.g. a make 1 knit stitch (mk1) as increasing stitch (which may look a bit neater) or a k2tog as a decrease stitch.
 [X]*Y, means, knit the sequence in brackets (X) Y times, e.g. [k2. kfb]*3 means knit the sequence "k2, kfb" three times.
Gauge and Size
In garter stitch 11 ridges (=22 rows) gave 5 cm in height, and 12 sts gave 5 cm in width.
The finished piece has about 48 to 50 cm of circumference (at the lower edge  ribbing) and is 23 cm high. However, the ribbing stretches easily to 56 cm circumfernce.
I'd advise you to measure the circumference of the intended wearer's head as well as the wished height of the crown.
Construction
Knitted flat an in a Ushape around the first magic CO. Each row consists of a garter stitch part (ribbing  at the beginning and end of each row) and a semicircular bit around the turning point of the U. The slope is achieved by changing the number of increases and decreases. See schematic below.

Construction  click to enlarge 
First there will be 4 decreases every 2nd row, which basically creates a semicircle above the ribbing. Then only 3 increases will be made, then only 2, then only 1 and finally there will be a few rows without any increases at all.
Once you've reached the middle of your piece, you will knit the same backwards, i.e. there will be decreases instead of increases. That means you start with no decreases, then switch to 1 decrease every 2nd row, then 3 decreases every 2nd row and finally 4 decreases every 2nd row. Until there are only 2x20 stitches left. The piece is finished with a threeneedle BO.
The letters in the schematic refer to the parts of the pattern instructions below.
Instructions
These are the specific instructions for a hat with the same yarn weight, same gauge and same size that I knitted. If you'd like to adapt the pattern, see "How to Adapt to Another Head Size  or Generic Instructions" below.
Do a magic CO of 2x20 stitches, i.e. you have 20 sts on each needle
Now turn your needles around in a way that you're looking at the garter stitch bumps.
All rows of the tip will be knitted in a Ushape, i.e. you knit the stitches on the first needle turn the piece upside down (this point will be called turningpoint ("TP") and knit the stitches on the other needle. Then you turn your knitting to the WS and knit back.
Part A
Row 1 (WS): k18, place marker, p2, TP, p2, place marker, k18  the markers will separate the ribbing from he upper (sloped) part.
Row 2 (RS): sl1, k17, [kfb]*4, k18  your piece will look similar to picture 1  the Ushape will not yet be visible
Row 3 (WS): sl1, k17, p to next marker (i.e. p4, TP, p4), k18
Row 4 (RS): sl1, k17, [k1, kfb]*4, k18
Row 5 (WS): sl1, k17, p to next marker (i.e. p6, TP, p6), k18
Row 6 (RS): sl1, k17, [kfb, k2]*4, k18
Row 7 (WS): sl1, k17, p to next marker (i.e. p8, TP, p8), k18
Row 8 (RS): sl1, k17, [k2, kfb, k1]*4, k18
Row 9 (WS): sl1, k17, p to next marker (i.e. p10, TP, p10), k18  now your piece will look roughly like photo 2; the inverted U will start to become visible.
Row 10 (RS): sl1, k17, [k1, kfb, k3]*4, k18
Row 11 (WS): sl1, k17, p to next marker (i.e. p12, TP, p12), k18
Row 12 (RS): sl1, k17, [k4, kfb, k1]*4, k18
Row 13 (WS): sl1, k17, p to next marker (i.e. p14, TP, p14), k18
Row 14 (RS): sl1, k17, [kfb, k6]*4, k18
Row 15 (WS): sl1, k17, p to next marker (i.e. p16, TP, p16), k18
Row 16 (RS): sl1, k17, [k4, kfb, k3]*4, k18
Row 17 (WS): sl1, k17, p to next marker (i.e. p18, TP, p18), k18

Illustrations 
Part B
From now on, there will be only 3 increases in every RS row.
Row 18 (RS): sl1, k17, [k6, kfb, k5]*3, k18
Row 19 (WS): sl1, k17, p to next marker (i.e. p39), k18
Row 20 (RS): sl1, k17, [k2, kfb, k10]*3, k18
Row 21 (WS): sl1, k17, p to next marker (i.e. p42), k18
Row 22 (RS): sl1, k17, [k10, kfb, k3]*3, k18
Row 23 (WS): sl1, k17, p to next marker (i.e. p45), k18
Row 24 (RS): sl1, k17, [k1, kfb, k13]*3, k18
Row 25 (WS): sl1, k17, p to next marker (i.e. p48), k18
Row 26 (RS): sl1, k17, [k11, kfb, k4]*3, k18
Row 27 (WS): sl1, k17, p to next marker (i.e. p51), k18
Row 28 (RS): sl1, k17, [k5, kfb, k11]*3, k18
Row 29 (WS): sl1, k17, p to next marker (i.e. p54), k18
Row 30 (RS): sl1, k17, [k13, kfb, k4]*3, k18
Row 31 (WS): sl1, k17, p to next marker (i.e. p57), k18
Row 32 (RS): sl1, k17, [k2, kfb, k16]*3, k18
Row 33 (WS): sl1, k17, p to next marker (i.e. p60), k18
A few rows into part B, your piece should look similar to illustration 3.
Depending on the length of your circular needles, you may switch from magic loop to just knitting without a piece of cord sticking out. When I reached that point, I put a stitch marker at the TP  this makes it easier to count your stitches if you want to make sure that you've increased/decreased correctly.
Part C
From now on there will be only 2 increases in every RS row.
Row 34 (RS): sl1, k17, [k20, kfb, k9]*2, k18
Row 35 (WS): sl1, k17, p to next marker (i.e. p62), k18
Row 36 (RS): sl1, k17, [k2, kfb, k29]*2, k18
Row 37 (WS): sl1, k17, p to next marker (i.e. p64), k18
Row 38 (RS): sl1, k17, [k10, kfb, k21]*2, k18
Row 39 (WS): sl1, k17, p to next marker (i.e. p66), k18
Row 40 (RS): sl1, k17, [k25, kfb, k7]*2, k18
Row 41 (WS): sl1, k17, p to next marker (i.e. p68), k18
Row 42 (RS): sl1, k17, [k13, kfb, k20]*2, k18
Row 43 (WS): sl1, k17, p to next marker (i.e. p70), k18
Part D
From now on there will only be 1 increase in every RS row.
Row 44 (RS): sl1, k17, k27, kfb, k to next marker, k18
Row 45 (WS): sl1, k17, p to next marker (i.e. p71), k18
Row 46 (RS): sl1, k17, k53, kfb, k to next marker, k18
Row 47 (WS): sl1, k17, p to next marker (i.e. p72), k18
Row 48 (RS): sl1, k17, k32, kfb, k to next marker, k18
Row 49 (WS): sl1, k17, p to next marker (i.e. p73), k18
Row 50 (RS): sl1, k17, k39, kfb, k to next marker, k18
Row 51 (WS): sl1, k17, p to next marker (i.e. p74), k18
Parts E
From now on, there will be no increases
Row 52 (RS): sl1, k to end
Row 53 (WS): sl1, k17, p to next marker (i.e. p74), k18
Measure the lower edge of the piece (at the garter stitch ribbing) when stretched comfortably. Check whether it measures half of your head circumference.
Part F (mirrors part E)
Row 54 (RS): sl1, k to end
Row 55 (WS): sl1, k17, p to next marker (i.e. p74), k18
Part G (mirrors part D)
One decrease per RS row.
Row 56 (RS): sl1, k17, k38, ssk, k to next marker, k18
Row 57 (WS): sl1, k17, p to next marker (i.e. p73), k18
Row 58 (RS): sl1, k17, k31, ssk, k to next marker, k18
Row 59 (WS): sl1, k17, p to next marker (i.e. p72), k18
Row 60 (RS): sl1, k17, k52, ssk, k to next marker, k18
Row 61 (WS): sl1, k17, p to next marker (i.e. p71), k18
Row 62 (RS): sl1, k17, k26, ssk, k to next marker, k18
Row 63 (WS): sl1, k17, p to next marker (i.e. p70), k18
Part H (mirrors part C)
Two decreases per RS row.
Row 64 (RS): sl1, k17, [k13, ssk, k20]*2, k18
Row 65 (WS): sl1, k17, p to next marker (i.e. p68), k18
Row 66 (RS): sl1, k17, [k25, ssk, k7]*2, k18
Row 67 (WS): sl1, k17, p to next marker (i.e. p66), k18
Row 68 (RS): sl1, k17, [k10, ssk, k21]*2, k18
Row 69 (WS): sl1, k17, p to next marker (i.e. p64), k18
Row 70 (RS): sl1, k17, [k2, ssk, k29]*2, k18
Row 71 (WS): sl1, k17, p to next marker (i.e. p62), k18
Row 72 (RS): sl1, k17, [k20, ssk, k9]*2, k18
Row 73 (WS): sl1, k17, p to next marker (i.e. p60), k18
Part I (mirrors part B)
Three decreases per RS row.
Row 74 (RS): sl1, k17, [k2, ssk, k16]*3, k18
Row 75 (WS): sl1, k17, p to next marker (i.e. p57), k18
Row 76 (RS): sl1, k17, [k13, ssk, k4]*3, k18
Row 77 (WS): sl1, k17, p to next marker (i.e. p54), k18
Row 78 (RS): sl1, k17, [k5, ssk, k11]*3, k18
Row 79 (WS): sl1, k17, p to next marker (i.e. p51), k18
Row 80 (RS): sl1, k17, [k11, ssk, k4]*3, k18
Row 81 (WS): sl1, k17, p to next marker (i.e. p48), k18
Row 82 (RS): sl1, k17, [k1, ssk, k13]*3, k18
Row 83 (WS): sl1, k17, p to next marker (i.e. p45), k18
Row 84 (RS): sl1, k17, [k10, ssk, k3]*3, k18
Row 85 (WS): sl1, k17, p to next marker (i.e. p42), k18
Row 86 (RS): sl1, k17, [k2, ssk, k10]*3, k18
Row 87 (WS): sl1, k17, p to next marker (i.e. p39), k18
Row 88 (RS): sl1, k17, [k6, ssk, k5]*3, k18
Row 89 (WS): sl1, k17, p to next marker (i.e. p36), k18
Part J (mirrors part A)
Four decreases per RS row.
Row 90 (RS): sl1, k17, [k4, ssk, k3]*4, k18
Row 91 (WS): sl1, k17, p to next marker (i.e. p32), k18
Row 92 (RS): sl1, k17, [kfb, ssk]*4, k18
Row 93 (WS): sl1, k17, p to next marker (i.e. p28), k18
Row 94 (RS): sl1, k17, [k4, ssk, k1]*4, k18
Row 95 (WS): sl1, k17, p to next marker (i.e. p24), k18
Row 96 (RS): sl1, k17, [k1, ssk, k3]*4, k18
Row 97 (WS): sl1, k17, p to next marker (i.e. p20), k18
Row 98 (RS): sl1, k17, [k2, ssk, k1]*4, k18
Row 99 (WS): sl1, k17, p to next marker (i.e. p16), k18
Row 100 (RS): sl1, k17, [ssk, k2]*4, k18
Row 101 (WS): sl1, k17, p to next marker (i.e. p12), k18
Row 102 (RS): sl1, k17, [k1, ssk]*3, k1, k2tog, k18  I chose a k2tog (instead of an ssk as the 4th decrease, to get a clean edge towards the garter stitch ribbing)
Row 103 (WS): sl1, k17, p to next marker (i.e. p8), k18
Row 104 (RS): sl1, k17, [kfb]*3, k2tog, k18
Row 105 (WS): sl1, k17, p to next marker (i.e. p4, TP, p4), k18
Now there should be the same number of stitches left that you started with, i.e. 2x20.
Turn inside out, hold right sides together and do a three needle BO of the last stitches (see illustration 4).
Weave in ends and turn back right sides out.
How to Adapt to Another Size
If you have different gauge, have a different size head or use different yarn altogether, you can adapt the pattern to your size. Basically, you can adapt two things:
 the number of stitches on both ends that are knitted in garter stitch and that form the ribbing  the height of your ribbing  and
 the number of rows with 4 in/decreases, 3 in/decreases, 2 in/decreases, 1 in/decrease and no increase  this changes the shape of the slope.
If you'd like a shorter/longer ribbing or use different yarn, I'd suggest that you cast on fewer/more stitches with the magic CO. On each needle, you need the intended number of ribbing stitches plus 2.
I'd suggest that of the total number of rows you need to reach the middle of the piece,
 you use about 1/3 for RS rows with 4 in/decreases
 about the same number for RS rows with 3 in/decreses
 about 1/6 for RS rows with 2 in/decreases
 you devide the remaining rows equally into rows 1 in/decrease and no in/decrease.
As you can see in the instructions above  for me it was a total of 26 rows to reach the middle, 8 of which with 4 increases, 8 with 3 increases, 5 with 2, and 4 with 1 increase  which is roughly the distribution above.
When you change from 4 increases to 3 increases, it's possible that you have a stitch count between the markers, that is not divisible by 3. In this case, you need to distribute the new increases as evenly as possible throughout the stockinette stitches. The same goes for all other changes in the number of in/decreases.
For a wider circumference, you can just add a few rows, without any increases or decreases in the middle of the piece. For a higher dome, do more rows with 4 and 3 increases, and fewer with 2 and 1 increases.
Important: With all adjustments, make sure to knit two equal halves, i.e. do the same decreases during the 2nd half then you did increases during the 1st. That's why I'd advise to take notes of the knitted rows.
Generic Instructions
With magic CO cast on the number of stitches you want for the ribbing plus 2 to start the semicircle increases and all of that on both sides of the needles (i.e. calculated number of stitches times two).
So your first row after the magic CO would be;
Row 1 (WS): k to 2 bef turning point ("TP"), place marker, k2, then turn, k2, place marker, k to end
Part A
You start with a few rows with 4 increases per RS row, ie.
Row 2 (RS): sl1, k to marker, between here and the next marker evenly distribute 4 increases (e.g. kfb) among your knit stitches  starting from a random stitch during the first quarter, slip marker, k to end
Row 3 (WS): sl1, k to marker, p to next marker, k to end
Repeat rows 2 and 3 until you've reached about a third of half your circumference
Important: Take notes of the number of repeats that you work for all parts. You'll need these numbers to do an equal amount of decrease rows.
Part B
Now you change to only 3 increases per RS row, i.e.
Row 4 (RS): sl1, k to marker, between here and the next marker evenly distribute 3 increases among your knit stitches  starting from a random stitch during the first third, slip marker, k to end
Row 5 (WS): sl1, k to marker, p to next marker, k to end
Repeat rows 4 and 5 until you've reached about two thirds of half your circumference  so roughly the same number of repeats in part A.
Also, take a note of the number of rows you worked with 3 increases.
Part C
Then you switch to 2 increases per RS row.
Row 6 (RS): sl1, k to marker, between here and the next marker evenly distribute 2 increases among your knit stitches  starting from a random stitch during the first half, slip marker, k to end
Row 7 (WS): sl1, k to marker, p to next marker, k to end
Repeat these rows about a half of the repeats of part A.
Part D
Then you switch to 1 increases per RS
Row 6 (RS): sl1, k to marker, between here and the next marker randomly do 1 increase among your knit stitches, slip marker, k to end
Row 7 (WS): sl1, k to marker, p to next marker, k to end
Repeat these rows for about half of the remaining rows until you've reached half of your circumference
Part E
Then to switch to no increases.
Row 8 (RS): sl1, k to end
Row 9 (WS): sl1, k to end
Repeat these rows until you've reached half of the intended circumference
Now you start the second half, ad you basically knit the mirror image of the first.
Part F
First the rows with no increases:
Row 10 (RS): sl1, k to end
Row 11 (WS): sl1, k to end
Repeat the rows the same number of times as in part E.
Part G
Only one decrease per RS row.
Row 12 (RS): sl1, k to marker, between here and the next marker randomly do 1 decrease (eg. ssk) among your knit stitches, slip marker, k to end
Row 13 (WS): sl1, k to marker, p to next marker, k to end
Repeat these rows the same number of times as the rows in part D.
Part H
Two decreases per RS row.
Row 14 (RS): sl1, k to marker, between here and the next marker evenly distribute 2 decreases among your knit stitches  starting from a random stitch during the first half, slip marker, k to end
Row 15 (WS): sl1, k to marker, p to next marker, k to end
Repeat rows the same number of time as the rows of part C
Part I
Three decreases per RS row.
Row 16 (RS): sl1, k to marker, between here and the next marker evenly distribute 3 decreases among your knit stitches  starting from a random stitch during the first third, slip marker, k to end
Row 17 (WS): sl1, k to marker, p to next marker, k to end
Repeat rows 16 and 17 the same number of times as the rows of part B
Part J
And towards the end, four decreases per RS row.
Row 18 (RS): sl1, k to marker, between here and the next marker evenly distribute 4 decreases (e.g. kfb) among your knit stitches  starting from a random stitch during the first quarter, slip marker, k to end
Row 19 (WS): sl1, k to marker, p to next marker, k to end
Repeat rows 18 and 19 the same number of times as the rows of part A.
Now there should be the same numer of stitches that you started with.
Turn inside out, hold right sides together and do a three needle BO of the last stitches.
Weave in ends, turn back right sides out and enjoy wearing your hat.