First, their glued seams attack the image, then some of the goodies in the paper take their turn. I am sorry to say, I speak from experience. Actually, not all paper envelopes are nightmares, just most of them. You can write on it. After all, you are a journalist and it would be nice to know what you had photographed, after old age or an overly pleasurable lifestyle dims your memory for specifics.
English photographers are very fortunate.
The Atlantis Silversafe products are among the best. Certainly, these paper envelopes are exceptionally safe if you sleeve the negative and transparency strips stored in them. You will probably want to do this anyway, just to lessen the chances of damage from abrasion, dirt, fingerprinting and careless handling. According to Henry Wilhelm, high density polyethylene seems to cause the least scratches when you move film in and out. You can also purchase longer 35mm and 120 envelopes, and sheet film envelopes.