The top measurer 12"x18" , you can use any thing in the middle as for padding. What every you have around that will make it padded. I just did it like a quilt, fabric for the top and back and padding in the middle and than the binding. The bag is 9"x14" I just made 2 bags put one inside the other and than folded over the top and sewed some plastic box strapping in it, that is what holds the bag open. I did sew a 2 inches strip of cloth to the top back of the bag at the top . Than I sewed that to the matt of the bag when I sewed on the binding. And you can do any thing you want to make it pretty , or leave it plain. Have fun .