Manufacturer Homtable. 50 x A7 Envelopes. A7 Envelopes 5 x 7 Card Envelopes. It’s available in a choice of colors. Size A7 (5.32×7.28). Open Design: The blank envelopes provide you with the freedom to choose the location of the label you want to paste; You can print, draw or write down words you like on the envelope to correspond to the subject.