How the flat fitted is made:

I used Little Comet Tails, One Size fits all pattern, but you can use any large diaper pattern. There are several for free online. For this tutorial I used cheap flour sack towels from Walmart, they run about a dollar a flat. I will say that it was easier to make with the GMD large flats. They are bigger/wider, thicker and of much higher quality fabric. Two of my flour sack towels had tears in the fabric after being washed!

Wash and iron the flats first. Take two flats, matching seams and right sides together then pin to keep from shifting.

This works best if you have two patterns cut, but I didn't, so I used pins to outline the edge of the pattern and repinned to get a better fit.

Example of how the pattern should be laid out.

Place your diaper patterns on top, with the front of the diaper (where the pocket opening will be) near the seam or serged edge on the bottom and the other one reversed on the top. It doesn't matter if the edge is pretty far from the pattern, just extend the line to the seam. This lets you skip a step when sewing and leaves enough extra fabric to fold over the flat insert.

Make sure one wing is at the very edge of the selvage. It sometimes takes a little adjustment if you only have one pattern. I pinned around the edge of the wing and part of the leg opening, and adjusted the pattern pieces to accommodate each other. Trace your pattern out with washable marker or pin.

Patterns pinned out to fit.

Cut out and sew the diaper together leaving the front pocket open.

 Cut out pieces.

Front pocket opening.

Sew together leaving front edge open.

Mark all elastic attachment sites for both diapers.

Attach one end of the elastic to the seam allowance using a zigzag stitch going back and forth to attach it firmly to the seam.

Stretch the elastic tight to the next mark, pin and sew. Cut off the extra elastic. Attach only the ends of the  elastic at marked points.

 Stretched out elastic.

Pinned at elastic mark.

Once all the elastic is attached, turn right side out and top stitch, making sure not to catch the elastic as you sew around.

 Top sew around edge.

 When you reach the elastic pull the seam out and carefully go around

Take your time here!

**Finished with the flat fitted!**

 This shows the pocket flap folded over to adjust rise.

Flat Inserts:

You will find you have two largish pieces when you are finished cutting out your diaper shapes. You can get two newborn flats out of these pieces. Trim the edges of one to make a rectangle and use that as a template for the next. The flour sack towels were pretty small and I could use a sheet of paper for a template.

You can serge or turn and top-stitch. If you turn and top-stitch, leave the selvage edge open, then you don't have to turn the edge under to keep from fraying.  Now you have a flat doubler or a newborn flat to go with your diaper.

Now you have 2 pockets and 2 doublers from 2 flats. If you bought a 5 pack from Walmart you will have three extra flats left. Cut one in half and turn and top-stitch each one like a pillowcase. You just made 2  small flat inserts for your flat fitteds.

The other two flats will be used to stuff for sizes medium to large. Now you have two flat fitteds that will fit any size baby with any flat insert combination, with doublers for night or liners to catch poo.

 Flat fitted with a flat insert.

 Stuffed and folded down to size.

Folded and ready to go! Very trim and easy to slap on a wiggly toddler.