Julie,Two suggestions I have for you:
1. Are you using an ink jet printer? I have never been satisfied with the quality of those printings, even when sealing properly. I switched to a laser printer a few years ago and have been much happier with my papers. If you only need a few papers done, you might see about having a local print/copy shop do them for you.
2. Have you tried sealing them in tape? You might see if that gets you better results. (Get a piece of clear packing tape, put down your paper, put on another layer of packing tape. Trim the tape down close to the edge.)
I show it here:
https://youtu.be/86R7QBst4_o