Blue Summit Supplies Tax Envelopes, 1099, Double Window, Security Tint, Gummed, 500 PackYour 1099 MISC forms will Line up Perfectly It can be so difficult to find envelopes that fit printed 1099 forms perfectly. Some will show the recipient's address but not the senders address, while others will hide parts of the addresses, and worse, others will show parts of the tax form like the personal tax number. So much for security. Our 1099 tax envelopes have a unique bottom window design so your personal info will always be hidden, and our