I purchased these clear vinyl envelopes to protect 11" x 17" architectural drawings while being used on construction sites. They protect the paper drawings from jobsite dirt and moisture, as well as damage from being handled daily. These envelopes are particularly thick vinyl, and are VERY high quality. I would recommend them to anyone looking for heavy duty protection of documents of all kinds.

 

I'm a landscape designer and purchase these along with the 18" x 24" size to keep our plans clean and dry in the field. So far my foremen love them, grabbed some magnets with a carabiner clip and will put them on the side of the truck or equipment on site so everyone can have access to the plans. Held up to quite a bit of rainy weather already too, with the plans still being dry and easily readable. Great tool to have!