I went hunting for weeks once, looking for the cheapest price AFTER shipping. It may have c hnaged since then, but some of those places have LOTS of variety.
There is a rnage of quality, expecially in glassine envelopes. I got some cheap ones from ULINE once, with somewhat ragged zig-zig-cut edge ("pinking shears"?) and the open end not pre-folded. The glue had also oozed out just a little so you had to pry some bags apart. But they were cheap and big and that was what I wanted.
