Interesting topic that of tinting canopies. I have done several Great Planes kits using black Rite Dye. The last one I did was my Giles 202, see picture. It was done in a 5 gallon drum using 2 packets of dye and hot water from the tap. After about 10 minutes it does not get any darker in tint and the black dye makes a nice bronzey type of a colour.

One thing that has not been mentioned in this thread is that keeping the canopy in hot water for any length of time can and usually does cause it to change shape a little. Try fitting your canopy to the plane before dipping it in the dye (nice tight fit) and then after the dye job and you will usually find that it does not fit as well, so keep this in mind when keeping it in real hot water.

Think I would like to try the Testors spay on type as mentioned.

Cheers

Mike