A quick little pattern hack to lengthen a sleeve.
I’ve lengthened the short sleeve from The French Dart Shift pattern to a 3/4 length sleeve, with finished measurements of 44cm long and a hem circumference of 28cm. Decide on your own measurements by measuring yourself with your arm bent at the elbow.
pattern master or set square
Trace your sleeve and extend the grain line. Mark the new length at a right angle to the grainline (don’t forget to allow for the seam allowance at the sleeve head). Below this mark your hem allowance – 3cm is good for a hand stitched or twin needled hem, but you get to decide!Fold the pattern in half so the underarm bicep points line up with each other (circled). The fold should run along or parallel to the grainline. Trace and mark the underarm of the sleeve. Draw the hem and the seam allowance lines, making sure they are at a right angle to the fold. Measure and mark half the finished hem circumference along the hemline (A) and then add the 1cm seam allowance and mark this point (B).
Draw a line from point B to join the hem to the underarm.
This is the trickiest bit to get your head around, but once you get the hang of this it’s really easy!
When the hem allowance is turned up, to sit properly, it needs to be the same shape as the sleeve.
Draw a line 3cm (or whatever your seam allowance is) above the FINISHED hemline so it intersects with the underarm seam (C). Then just draw a line at a right angle from it (running parallel with your fold) to intersect with the hem allowance (D).
When you press up your hem allowance up to finish your sleeve, it will be exactly the right shape!
Cut out the sleeve along the underarm and hem while it is still folded (pin together first). Unpin and then cut around sleeve head, and notch your pattern.
Annotate your sleeve with the style, variation and I like to add the date as a way of keeping track of the latest version.
Voila, you’re done! Just in time to keep warm in this chilly weather, and of course, you can do this alteration in reverse to shorten a sleeve.