Xs=4.25 x 5.5 - 20 Pcs, S=4 x 6 - 20 Pcs, M=5 x 7 - 20 Pcs, L=4.25 x 5.5 - 100 Pcs, Xl=4 x 6 - 100 Pcs.Each envelope features a convenient self-adhesive peel-and-seal strip with strong adhesion, eliminating the need for a separate glue stick. Both the blank invitation cards and their accompanying envelopes feature a double-sided design. The cardstock is of a moderate thickness, providing an ideal surface that perfectly absorbs ink from fountain pens, colored pencils, and watercolors-without any bleed-through to the reverse side. If you choose to print on the cardstock using a printer, the finished result will boast a stunning, professional-quality appearance comparable to commercial printing. Weight: 0.37 lbs.