9″ x 12″ 自黏白色目錄信封（5入）

I mailed a thick stack of tax papers and the 9x12 size fit everything without folding. The self-seal strip closed tight on the first try, no licking or sponge needed.

The peel-off strip actually seals flat without any moisture, which is way easier than licking the old ones. I used them for mailing tax documents and nothing shifted or tore in transit.

These fit a full stack of 8.5x11 printouts without cramming, which is more than I can say for the thinner ones I've used. The self-seal strip is the real win though, no licking, no sponge, no mess at the counter.