Definition: Flat knitting is the method of knitting back and forth in rows, turning your work at the end of every row, alternating the sides that face the knitter. In contrast, the right side of the work always faces the knitter when circular knitting.
I thought I would answer a question asked by some knitters – How do you convert sleeves knit in the round to ones knit flat? Sleeves knit circularly are most commonly worked by picking up stitches around the armhole (drop shoulder style) from the body of a sweater that’s also been knit in the round. The stitches are joined and knit in rounds to the cuff, decreasing along the inside arm to reach the required number of stitches at the wrist. An alternative method is to circularly knit a separate sleeve, usually because there is a cap versus a drop shoulder, then it is sewn into the armhole. You can certainly knit either of these sleeves flat, but I would question why you want to do so, or why you’re deviating from the design’s instructions. I probably would not knit sleeves flat if the body of the sweater was knit in the round, because it is trickier to sew in the sleeve; it is similar to stitching a sleeve from a sewing pattern. If I chose to do so, I would convert the whole pattern to flat knitting. Regardless of your choice, I will show you how to convert circular knit sleeves to ones knit flat.
Drop Shoulder Sleeve
Drop shoulder sleeve styles knit flat begin at the lower cuff or edge, working towards the straight top edge, that fits into the armhole of the front and back pieces. A number of stitches are increased after the cuff is made to reach the stitch number at the sleeve top or upper arm. The measurement of this straight edge is usually double that of the armhole depth. For example, if the armhole depth is 10 inches, the width at the upper arm is 20 inches, because the sleeve needs to fit the depth of both front and back pieces.
The key measurements are the wrist and width of the upper arm. The number of stitches to cast on for the width of the wrist and the number of stitches at the top edge will be approximately the same as those given in the circular knit instructions. I suggest recalculating the stitch numbers to check the accuracy of the gauge. In the schematic below the number of stitches to pick up for the top edge is given as 48, with the stitch gauge at 4/inch, therefore 48÷4=12inches, the exact measurement given in the instructions for the upper arm circumference (K). Thus you can use this same number (48) of stitches given in the pattern for the top edge of the flat knit sleeve. Repeat this calculation for the wrist or cuff.
Because the stitches are decreased at the inside edge of a circular knit sleeve, working down to reach the stitch number at the wrist, flat knitting a sleeve works in the reverse. You’ll need to increase instead of decreasing stitches to reach the stitch number at the upper arm. If you obtained the same row gauge as in the circular knit sleeve pattern, the increases should correspond to the decreases. If the gauge is different or you want more fullness, you’ll need to figure out the placement of increases to maintain the correct measurements.
Note: If the garment sleeve consists of a pattern stitch with multiples, ensure that the pattern is aligned correctly.
Sleeve With Cap Shaping
To flat knit a sleeve with a cap that was originally knit in the round is fairly simple. As long as your gauge is accurate use the same stitch numbers as in the instructions to cast on, and of course don’t join your work. You may decide to move the increases further in from the side edges (which was the beginning of the round). The cap of a separate circular knit sleeve is usually worked back and forth to shape it. Again, as long as your stitch and row gauges are accurate, no adjustments are needed to shape the cap; just work it as in the instructions.
It’s not that difficult to convert a circular knit sleeve to one knit flat. First, decide if it is really necessary to do so. Knitting a sleeve flat from circular instructions requires checking that the gauge is accurate, and it’s likely that you won’t have to change stitch or row numbers. Also you will have to use increases instead of decreases for drop shoulder styles, and possibly adjust their placement.