A Peculiar Need

A Peculiar Need

I'm full of peculiar needs. I need some dust covers to go over the ends of the telescope tube assemblies. I'm thinking either elastic bowl covers large enough to go around a 20" diameter bowl (so like something a restaurant would buy), or shower caps that you might find aboard an alien spaceship--especially the bigheaded aliens that the original Star Trek series so often used.

Any hints? I've tried Google, but looking for 20" bowl covers isn't doing the job.

UPDATE: Large (22" diameter) stuff sacks, such as are used for large sleeping bags, have been suggested. Since I am going to have to create a light shroud for the telescope anyway (attached to the tube ends with Velcro), I may just buy a little extra, and some elastic, and make the dust covers myself. Hey, at least I am not going to make the cloth myself!