Thanks, Steve. Those are mighty deep side pleats. If my apron is 18 inches wide that would make them about 8 or 9 inches deep. Is that what you meant to say? Hmm. That's like three aprons worth of fabric in front, not counting the inner apron. I'm not trying to cut back on fabric, but I think I'll go more moderate. It seems that for apron-dropping purposes, 4 or five inches deep would be sufficient. That would give 16 to 20 inches of fabric to unfold as knees spread, giving a minimum of 34 to 38 inches to hang knee to knee on me, which is a lot.

I'm thinking perhaps you meant that all the hidden fabric in the deeper side pleats equals half the apron width, meaning for an 18 inch apron they would use 9 inches of fabric and be 4.5 inches deep. Is that right?

Regarding denim seams shrinking, one thing is for sure, they use cotton thread on jeans, which itself will shrink differently from the fabric. Good to point out that hazzard, though. So have you tried doing denim with maybe an all polyester thread, or a blend? Another trick would be to use a zigzag stitch, but that would probably look funny. I have in the past put hems on jeans that never puckered with many washings, so that must have been poly or cotton/poly blend thread.

I also noticed on the jeans that I have that the stitch they use is somehow not just an ordinary straight stitch, so that may figure in as well.

We shall see, we shall see.

I've also been warned by a seamstress to beware of selvage that may have different fibers or weave, and therefore shrink differently than the fabric itself.