As promised, here is a step-by-step photo tutorial on how to make an origami envelope which is large enough to hold a typical ATC card or small greetings card.
To start, you will need an A4 piece of paper. I used a sheet of a Gelliprint that I made using chocolate coin impressions.
First, with the sheet laid out landscape, fold the A4 sheet in half
Open the sheet out and then take the right hand corner (plain side facing you) and create a triangle, bringing the corner up to the top edge
Now bring the bottom left hand corner up to meet the right hand triangle that you can see here in the photograph
Fold this section up as you can see here using the crease you’ve made
6. Measure four centimetres and make a crease along the left hand side, folding it backwards. Then measure approximately 7.5 centimetres and create another vertical crease.
7. Open the sheet out fully and make a curved mark with your thumb nail
This will form your concertina fold leaf. Carefully fold the section backwards and forwards along the curve until you have a flexible fold to work with
8. The crease you make next is the opened out triangle you can see in the above image, on the right.
9. As you can see here, the crease arcs from the top left to the bottom right.
Fold backwards and forwards alternately as if you were making a fan with evenly spaced folds.
Refold your paper until you have your concertina section on the righ. Hinge the lefthand triangle in the right pocket
Adjust your leaf as necessary, until you’re happy with it
Happy folding 🙂