Jackets can be made for the Amazon cover either with or without batting inside. The first one (post of March 14th) was done with batting only for the part covering the outside, not the flaps that are inside. The reason for this limitation is not to make it bulkier on the inside. The simplest way to make the jacket is to skip the batting, as it only makes it more complicated and now having done one without batting, it works just as well.
Cut 2 pieces of a fabric you love, 9-1/2" x 18," one for the outside which shows, and one for the lining. Or if you do not have enough for two pieces, cut the lining from a coordinating fabric.
Place these two pieces right sides together and sew a 1/4" seam around the edge.
Do not sew all the way around; leave an opening you can get your hand inside to turn right side out.
When you turn it right side out, use something blunt like a chopstick to push out the corners to be as close as possible to square; don't use scissors because they are sharp enough to make a hole and then you will have to start over.
When the jacket is right side out, press it and hand sew the opening you left, or machine sew close to the edge.
Wrap the jacket to the inside of the cover, front and back. Hand or machine sew the top and bottom edges so that the folded over part makes a little pocket to slip the cover into.
If the Kindle is already in the cover, it works best to slip the jacket on the back part of the cover first and then the front. The finished jacket is below.