Old Tool, New Use

How do you make a template to address navy blue envelopes?  The envelope paper will be dark so you won't be able to use a light box. Each envelope will have to be hand lined. How do you make a template so the process will be a little bit faster?

I was pondering this problem while I was eating a piece of Himself's birthday cake. As I was enjoying the chocolately goodness of the Devil's Food cake, I happened to catch sight of the cooling rack on the table. Light bulb!

Since the bride wants her envelopes addressed in Copperplate, the width of the rack would be perfect as baselines. A quick wash and dry of the rack and down to the drafting table. I found a black piece of scrap paper  to use as a test. The paper was positioned under the rack and lines were drawn using a slate pencil. The slate pencil lines were easily erased and didn't leave too much of a residue on the paper.

You can bet I'm insufferably pleased with myself. Hopefully, this application will work on the real envelopes. I haven't seen them yet. Don't know if the paper has a matte finish or is slick. Keep your fingers crossed for me.

Have you ever used a tool for a different application than it was meant to be used?