There was a lot of interest in this part so I’m adding another blog entry.
In the past I’ve used guitar string: burns nicely but abrades the line so it isn’t very dark; bailing wire: gets too hot and scorches the wood around the line and leaves a heavy carbon deposit that can flake off; and even copper wire: conducts heat so efficiently that it doesn’t work.
Then awhile back Captain Eddie mentioned burning lines with plastic laminate (Formica). So I stopped by the local Borg (Lowes/Home Depot) where they have walls of free, small, plastic laminate samples and picked out the ugliest, brightest color sample (so I won’t lose it). I start the line with a either a skew or diamond shaped carbide tool, cut a few millimeters deep, then hold the edge of the Formica against the cut line at around 2000 rpm. It heats up quick and burns a nice clean, black, line. Give it a try, works great.
The samples can be found in the countertop/cabinet section and look like these:
Here is a close up of the nice dark lines using this method: