Pro Art-Strathmore Correspondence Cards And Envelopes. Strathmore Writing paper delivers the ultimate handwriting experience. Preforms beautifully with a broad range of writing instruments including fountain pens. This package contains twenty 6-1/2x4-3/4 inch envelopes and twenty 6-1/4x6-1/2 inch correspondence cards. Acid free. 25% cotton. Made in USA.