Envelope Addressing Guides. Perfectly address invitations, cards, letters, and more! For writing and calligraphy. Templates cover the 5 common envelope sizes. Durable clear plastic stencils. Instructions included. Package measures 9.75" wide x 5.75" high (24.8 cm wide x 14.6 cm high). Includes 4 templates for the most common envelope sizes: A7 invitation and greeting card envelope template ruled for print writing, A7 envelope template ruled for calligraphy, A1 response card and thank you note envelope template, #10 business envelope template, with guidelines for A4 and A2 envelopes.