1.   The automatic sorting machines cannot always cope with colored envelopes.

2.   Big envelopes, colored envelopes, envelopes of odd shapes.

3.   Big colored envelopes.

4.   Buy some card stock and matching colored envelopes, available from computer and office-supply stores.

5.   It ought to stick out amid all the brightly colored envelopes, on account of all the cut-out letters used to spell out the address.

6.   To get children started in the card business, the program includes colored envelopes, paper, stickers and crayons.

7.   Use a colored envelope or box.