I am going to "help "my adopted niece (6) make a table runner for her family for Christmas. She wants it to say I love you with a patchwork heart, I'm figuring 24x36 & have the basic plan down(using scraps so not an expense for me.my question is I've got a big piece of red felt can I use that easily as the backing? Will it shrink or loose it's dye--- I don't think it's the most expensive felt(it was given to me)should I wash it first?