Marie Coffin and knj09705 both asked about the transition between the flat-felled seam and the split side seam on Sam's shirt... thanks for showing an interest! and since I happened to making another shirt hot on the heels of the previous one I snapped a few pictures to demonstrate how I did it...
btw: I've checked out some of the better rtw menswear shirts and there's a choice of finishing methods. So the following is not the only way to construct this feature, but this is the way I chose this time. I wonder... is there even a "right" way?
Stitch the seam down to the point at which the slit is to start. I left an unfinished length of 10cm for the side seam splits on both of these shirts...
Trim this seam allowance to half its current width, with the trimming tapering off for the last couple of centimetres to the level of the slit. Also, snip into the seam allowance of the other side to the endpoint of the side seam (pictured below). Leave both slit seam allowances untrimmed.
Now press the untrimmed seam allowance back over the trimmed seam allowance.
Turn the top allowance under, tucking it below the trimmed seam allowance underneath to encase it, and press. Also, turn under the seam allowances of the split seam on both sides, and press. Pin.
Stitch the seam allowances down, close to the pressed edge. Stitch the short split seam allowance down separately.
For flat-felling the sleeve seam allowance: while stitching longitudinally along a tube-like structure such as a sleeve; ALWAYS stitch from INSIDE the tube. This eliminates the possibility of inadvertently catching down the other side of the tube by mistake. And yes, with my machine I always have to stitch a tube seam in two stages, from the middle, out to each end!
Lastly, stitch across the top of the split seam to stabilise and strengthen the top of the split. You could stitch a bar tack by narrow zig-zagging, or alternatively run a few forward-and-reverse passes of stitching.
Attempting to show the finished flat-felled sleeve and side seam in entirety. Not much to see at all, really ... but that's the whole idea! Nice and neat and tidy :)
