Pro-Art 62105912 Strathmore Artist Trading Card Frame with Envelope, 3-Inch x 5-Inch, 6-Pack Creates swap and collect original artwork These cards are a great way to meet other artist and share your work Perfect for art collage and mounting artwork Package contains six 4-7/8 x 3-1/2 Inch blank white cards and six 5-1/8 x 3-5/8 inch white envelopes It is acid free