Homebrew PCBs

While wishing that I had made a prototype first, mostly because it's 
a good idea and a lot of fun, I came up with an idea for soldermask.

Since we can use toner transfer for adding a silkscreen layer over a 
board, why not use toner transfer for adding a soldermask layer to 
the board? It could be even done in your favorite board color by 
using a color laser printer from a copy center. A negative image of 
the soldermask layer would be required. My software generates that 
if needed. The plastic toner soldermask layer would make an 
excellent barrier.

The next step would be to see if one could lay the toner transfer 
silkscreen layer over the toner transfer soldermask layer 
successfully with different colors?

My board (35mm x 40mm) can be panelized 25 times on one 8.5 x 11 
sheet. Even more on a legal sheet or larger. They use to charge $1 
for each sheet. So that's something like 5 cents per board after 
taxes.

If my rookie bare bones board design is ok when it arrives, then I'm 
going to try this idea.

Thoughts?

Mike