Writing on Autograph Quilts

When I first thought about collecting the autographs of my fellow medical bloggers attending the BWE in Las Vegas, I started out with this small quilt.  I wanted a quilt with minimal or no white with neutral colors that might look okay in most decors.  I went with blues and browns.  This quilt is 22.5 in square, machine pieced and hand quilted.
Here is the back with the quilt label.

I thought I would be able to find pens/ink that would work on the darker colors.  As you can see from my samples here, I was wrong.   I wrote on several of the fabrics, then washed the samples.  All the inks are “permanent” and “acid-free”The Sharpie fine tip in black and blue both work on some of the blocks, but not the darker browns. 
I have made another autograph quilt (to be shown next week) with white strips to be written on.  As you can see from this sample, the white gives us many more choices for individual signatures.