Choo Choo! All aboard for the big birthday bash! Celebrate your little conductor's big day with these festive invites! Minimum order of 20 pieces, 5 inches x 7 inches printed on 120 lb white eggshell felt, comes with a plain white, square flap envelope. Envelope liners & Colored Envelopes with contour flap are available at an additional cost. Different back and liner variants available via email.