This letter fold is not a quick and easy one. It will take you several minutes and involve you in some folds that require accuracy to work well. The effect, however, is rather good. Use it for that special person that you want to impress.
The front view is on the left of this page while the back view is on the right.
The brown paper that I have used to demonstrate the model here is the same basic color on both sides. The front differs by having a slight shine, some green leaves in one corner and dark brown edges.
It does not give a good indication of how the model will look with paper that has a different color on both sides.
A large section of the "back side" of the paper is apparent (on the back of the model.) The only part of the "front side" of the paper that shows is the border areas. Write on the colored side of the paper for this model, leaving wide margins.
Here is the Crease Pattern for the basic model.
I have included a few instructions and explanations on the CP. It is not particularly intuitive, however. I am working on the diagrams.
Fold from the colored side.
Start with the horizontal and vertical creases on the mid-line. Divide the model in 4 equal sections lengthwise. Turn the end corners over to make creases. You will need these later.
Use the folded corners to make a crease that will give you an edge column on the short side that is the same width as the edge column on the long side. Use this crease as a marker to make the diagonals that will be your outside edges on the completed model. Leave folded.
Hold the flaps down firmly and refold the edge column through both layers. Accuracy is very important here.
You should now have two creases that define the edge of the central column that consists of the paper that is in excess of the perfect square formed by the side pieces. Fold these creases to the center line, making a crease between them: valley, mountain, central, mountain, valley folds. Collapse the central column. Leave the locking creases for later or you will probably be tempted to crease them at 45 degrees. Don't. This will result in excess bulk during the next steps and make it difficult to make a flat model rather than a strained one.
Now we start the final collapse. Turn over the outside edges (which will lock your central column well enough). Just fold the corners flat at this point. Fold the corners to the center of the model, one at a time. Crease from the center point to the outer edge, not the other way around. The want those corners to meet in the middle.
You have now made enough creases to make the lock folds accurately. You can unfold the model and put these in at this stage, if you want. They make the overturned corners on the back of the model look neater. However, they make the model hard to open quickly, which is what you generally want to do with letters.
Having done that (or not) fold the edges over again and bring the corners to the center. Now make the corner flaps into windmill ends. (Collapse on the lines in the diagram if you are unsure how to do this.) Two of these flaps will rest on the central column so that the ends can be tucked under it. Pick one and tuck the end firmly under the central column. Folding clockwise, place the adjacent corner over the top of the one you just tucked under the column. Fold the next corner over this one and tuck its flap firmly under the central column also. Thread the final corner under the flap you first folded.
That's it. If you want to make your model stay really flat, place a slightly damp cloth over the top and iron through this. That should fix it.
Open it up. Write a nice note to a friend or lover, refold, and send or deliver the letter.
(It this is as clear as dishwater you may want to purchase the diagrammed instructions for a couple of dollars after I've finished them and posted them on my Ori-Berry-Gami shop on ETSY.) It will be up and running in a few more days
The model works for A4 but the fold over flaps are fairly small. This variation provides longer flaps, and looks a little more like a windmill.
The folding is the same except for the way in which the corner edges are folded. Consult the crease pattern to see where the creases are and what your reference points are. After you've done one the others will be easy. After you fold the long diagonal line the shorter line will appear by magic as soon as you flatten the corner.
Collapse the front as before. This time you will have a larger flap to tuck under the central column which will make it more secure.
Here is the crease pattern for this one. Note the differences.
You can modify the basic pattern in other ways as well. Here are some examples.