We use the little coin envelopes for employee ferry fare on jobs where we have to take the ferry. They are just a perfect size for us and I write on the outside indicating the name of the person the amount inside the date and name of the job that they are to be applied to. When the individual has used the money they are to turn in a ferry receipt so they just put the receipt back into the envelope and return to me for my bookkeeping. The only complaint I have about these envelopes is that the glue on the flap isn't very effective. I wet the flap and glue it shut but always reinforce with scotch tape to make sure they don't come open.
I purchased the #1 Brown Kraft Coin Envelopes for a Sharing Tree Gift Tag project. They were very sturdy and the perfect size to use with address labels for easy printing. The envelopes were easy to use - easy to find in the store. You can even use the neon colored (High Visibility) labels for a different look and to add color to them. We hole-punched the corners and wove curling ribbon of different colors to add a festive look. The directions for the project were folded and put into the envelope before we hung them on the trees.