Contact printing paper to paper...what to put underneath?

[BetterSense]

I have a pinhole camera and shoot paper negatives and make contact prints. I put a sheet of glass on top. But does it make a difference what surface I use? The bottom of my enlarger is white, but I was wondering if using black construction paper would be better so as to supress back reflections.

 

[sun of sand]

I think a piece of material would be better
towel or felt or t-shirt

 

[BetterSense]

Hmm sheets of black felt are only $.33. Maybe I'll do a test.

 

[bnstein]

All the contact printers Ive seen have a layer of something like felt (mostly green) so Id head in the 0.33 direction