Shoe is right, but I've had good luck with seeds on coffee filters. I do move them around as they dry, so they don;t stick. Also, my saved seeds are usually wet with rain, not plant juices, and that may make them less sticky. But I never tried paper towels.
And seriously: very few people bother with any dessicant inside the jars.
Another quirk I picked up from reading: try to avoid setting a packet of seeds down on wet surfaces or muddy soil. It will absorb water, bugs may crawl in, and mud may contain mold or spores. If you're going to put an envelope back into a jar with your entire stash of saved seeds, it must be dry, and probably should be pretty clean, so it doesn't encourage mold.
Probably few people worry about that either, but I usually decide how much I want to sow before going outside, and put that much into a Ziplock or envelope that I don't mind getting wet and dirty.
I also usually make a plastic marker for each variety I'm going to sow, before going outdoors, because I KNOW I will forget which is where within minutes.
