Add-On Envelope Books
These envelope books keep coins, stamps, and other small collections in order, and they expand easily
Source: Kids Good Things 2006
Variety of envelopes
Key chain or loose-leaf ring
Decorate a variety of interesting envelopes, such as those used for CDs and airmail, with rubber stamps, vinyl lettering, or labels.
Stack envelopes of the same size, and punch a hole in each (for thin paper, reinforce the corner with a plain round sticker before punching). Insert a key chain or loose-leaf ring into the hole, and add more envelopes as needed.