I have been sewing letters. They are scrap quilting fabric on the top and backing with scrap batting in the middle. I cut out about 5-6 inch squares of all three layers. I trace the letters with a silver pencil, sew on my marked line and then use pinking shears to cut the edges. I put a dot of fray check on the start of the seam . I think that you could put magnets in them but I am not. I am sending these to my grand daughters. I am going to add to the upper case set over time and do lower case letters and numbers.
Here is the free templates for the alphabet. It is for applique letters so some are reversed, easy enough to fix!
I was inspired by a pinterest post that my sister sent to me. I love the internet! Here is my start!