How to make an envelope from A4 paper: sizes, a printable template and folding

A pocket envelope is made from one piece of paper: a front panel the size of the finished envelope, two narrow side flaps, a deep bottom flap and a shorter top flap. Laid out flat it is a little under twice the envelope's height and the envelope's width plus two flaps. That means one A4 sheet comfortably makes an envelope for an A6 card or postcard of 105 × 148 mm, the same size as a standard C6 envelope.

Bigger cards need bigger paper. An A5 card (148 × 210 mm) needs a template of roughly 250 × 300 mm, which does not fit on A4, so print it on A3 or Tabloid if your printer takes it. Always make the panel 3–5 mm larger than the card on each side, plus a little extra for the thickness of what goes inside, so the card slides in without bending.

Measuring and drawing an envelope by hand works, but a printed template is faster and gives straight, matching folds every time. A good template has a solid cut line around the outside, dashed fold lines between the panel and each flap, and shaded strips on the bottom flap showing where the glue goes. Print it at 100% or Actual size, never Fit to page, or the envelope comes out a few millimetres too small for the card.

Foldpic includes a matching envelope in the gift kit for every project, sized automatically to the finished card, zine or calendar and coloured to match the design. There is also a free envelope template at /tools/envelope-template where you type in any card size and download a ready-to-print PDF with the cut, fold and glue lines drawn in.

Cut along the solid outline with scissors, or with a craft knife against a ruler for straight edges. Score each dashed fold line first by running an empty ballpoint pen along a ruler; on paper heavier than 120 gsm this stops the fold from cracking. Fold the two side flaps in towards the centre of the panel.

Next fold the bottom flap up over the side flaps and glue it down along the shaded strips, pressing firmly for a few seconds. A glue stick is tidier than liquid glue and does not wrinkle the paper. Slide the card in, then fold the top flap down and close it with a sticker, washi tape or a dab of glue. Leave it open if you are handing the gift over in person.

For an envelope you hand over, any 90–120 gsm paper works and coloured or kraft paper looks lovely. For an envelope you post, use at least 100 gsm so it does not tear in sorting, and keep it rectangular and flat. Write the address on the plain front panel; printing a design on the front is fine as long as the address area stays clear and light-coloured.

If the envelope is decorated all over, stick a plain white address label on the front. Postal rules for envelope sizes vary by country, but a C6-sized envelope, which is what an A4 template for an A6 card produces, is a standard letter size almost everywhere.