A1 Envelopes - Rainbow Mix - 3 5/8 x 5 1/8 (for response cards) (60pcs) Envelope Size: 3 5/8" x 5 1/8" Fits Card Sized: 3 1/2" x 5" 60lb paper weight (standard envelopes) Square Flap (gummed) 60 envelopes / 10 each of: red, orange, yellow, green, bright blue, purple