I was sure I’d done a tutorial on how to find the grain line on a sleeve but I can’t seem to find it now that I need to show it to someone. If it is a repeat ~sigh~ it’s likely not the first nor last and I apologize. If this proves to be of interest, I may show you how to do this on a two piece sleeve.
An aside for those who have already mastered the material in this tutorial; I’ll bet you didn’t know that if you intend to place a match stripe going over the sleeve to match a stripe on the front and back of the body, you have to do the sleeve first. Sure you might get lucky if you don’t do this often but if you’ve had to do match stripes as often as I have, starting with the sleeve is the only sure and fast way to do it correctly. If you’re not sure what a match stripe is, here’s two photos. You can click each photo to go to the original entry in which they appeared.
On the left below is a picture of our sleeve without a grainline. The first thing to do is to mark off the seam allowance as shown (right).
Draw a line connecting those two points (below). For better or worse and whether you intend it to be or not, this is your cross grainline (below).
Now you need to line up an L-square (left). At right below is the grainline.
Ideally, if you were going to place this on a horizontal stripe, the cross grain would be useful to ensure that the stripe around the sleeve will match at the seam line. Well, not this particular sleeve since it’s got a dart at the elbow but I think you know what I mean.