Jim -- 14x17 negatives...you're the man!
I believe Yupo comes in a couple different weights. I am using some 14x17 x-ray film for tissue support. It does save time to be able to pour big tissues and cut them down as needed. I pour three 14x17 tissues at a time and that uses up an entire batch of glop (about 280ml per tissue). Each tissue then gives me four tissues for 5x7 negs, or six tissues for 4x5 negs. Not quite big enough for two 8x10 negs (but good for one 8x10 and a couple smaller ones.)
I'll be pouring tissues tonight!
PS -- one thing about x-ray film...it fixes out quickly!