What is it?
A flat diaper is one of the first types of diapers ever made, and now one of the hardest types of diapers to find online.  Its basically a square or slightly rectangle shaped one to four-layer piece of material.  They are either hemmed or surged around the edges.

Sizes
They can come in sizes, or one-size that need to be folded differently to fit each size of child.

one-size – 27×27 inches (69 cm).

Newborn – 19×19 inches(50 cm) ;
Medium – 24×24 inches (60 cm);
Large – 30×30 inches (75 cm).

Materials Used
Most commercial flat diapers are made from cotton, hemp, bamboo, or polyester.  Stitching is a cotton or polyester thread.  Sometimes fleece or flannel are used as well.  The flats that I sewed were made from t-shirt material (basically cotton), they can also be made from old sweaters (think college sweater or hoodie).

Sewing Flats
These are by far the easiest to sew.  You simply cut one to two squares of whatever material you choose to use and either hem or serge the edges together.  Voila, you now have a flat cloth diaper.

How they are used
I commonly refer to these and prefolds as the “fold-fold-fold-pin” diapers to my DH because he gives me weird looks if I say “it’s a flat diaper.”  After being folded, the diapers are either pinned, snappied or some people opt for just putting them inside a wrap, cover, or woolie  and then attaching that to the child.  (of course this takes a cooperative child and a very good fold.  There are many different types of folds, but two main ones.  The Triangle and the Origami fold.  For prefolds there are a lot more!  (pictures will come in November when I have a model).

-The Triangle Fold.
The easiest of all folds, and the one my mother used on me and my siblings when we were in diapers.  While it doesn’t make a “pocket” for poo collection, it does make a very easy fold when you have a fussy baby.  As long as you have a good cover and don’t let any of the diaper hang out of it, you should be fairly well protected from blow-outs and leaks.

1. Bring corners of the diaper together, forming a triangle.
2. Bring two outside corners together (halving the triangle)
3. Place baby on diaper with the shorter point facing down.
4. Bring the three corners together and secure with pin or pins. (some people can manage to get the pin through all three layers, some need to use two pins.  No big deal) You can also use a snappi on this type of fold.
5. Cover with cover, woolie, or wrap.

- The Oragami Fold
One of the more fun types of folds in my opinion.
1. Quarter the diaper (Fold in half twice)
2. With the point of the diaper to the bottom left of the diaper, grab the top-right corner and pull it across till it forms a wide triangle and leaves the bottom-right corner in its square position.
3. Flip the whole thing over, keeping the long side of the triangle at the top of the diaper.
4. Take the square part and fold it over on itself (in a rolling sort of manner) about four times until it makes a thick piece in the middle of the large triangle.
5. Place the baby in the middle.
6. Fold up the front and fold over the two sides (you can fold them in first to make a bit of a squared edge if you wish, but its not necessary) This makes a nice little “pocket” in the back for the capture of poo.
7. Bring the wings over the middle and pin or snappi.
8. Cover with your choice of covers.