Memory Quilt using knits and layer cakes
 

I've still got on my list to make a memory quilt out of my niece's clothing for my great niece. Here's my question: I wanted to make the disappearing hourglass. I've ironed light interfacing on all the clothes I'm using and plan to cut them into layer cakes. I bought a solid white layer cake and will sew them according to Jenny Doan's tutorial, with a 10" square out of my niece's clothing to a 10" square from the layer cake. What I'd like to know is, will I also have to iron light interfacing on the layer cake pieces so they will be about the same weight.

Thanks, everyone.

Unless the clothing plus interfacing is substantially heavier than the layer cake, you should be OK. People mix different weights of fabric in the same quilt all the time.
It's very kind of you do to this for her.

You shouldn't need to interface the layer cakes. I've made several and never have and haven't had a problem.

Just be careful about the bias edges that I think with this pattern you will have to deal with.