That's it.
I probably should do an illustrated tutorial, since it's not really difficult, but exacting: a variance of more than 1/16" can make a jacket either too tight or too loose.

Each jacket is in five pieces: spine, front and back covers, front and back flaps.
Working outward from the spine, each piece overlaps the one next to it by slightly more than 1/2" (that is, the spine overlaps the front and back covers, and the front and back overlap their respective flaps.)
That overlapped area is where the two-sided tape is applied, on the front of the piece being overlapped / back of the overlapping piece, so what you wind up with are seams at each place where the cover goes around a corner. It makes a strong seam, relatively invisible if you make sure there's either a dark line or two dark colors there (and remember to run a marker along the edge of the paper to prevent a hair-thin white line.)
I've tried a number of different papers, and currently I'm using a 48# Kodak Gloss Photo paper (partly because it was on special), but a Matte finish works just fine too.

Ah, the meek. Playing the long game.
Sneaky bastards.

--Denise Mina, Field of Blood
Last Edited By: James Friel Nov 20 10 7:58 PM. Edited 3 times.