Colour changing mugs

[quasar]

Has anyone printed onto blue colour changing mugs before?
I was asked to put a black logo on a blue mug, and was surprised that my first test worked well, but when it cooled down you can still see the logo.
is there only certain colours you can use with a blue mug?

[Paul]

I did try them. red, blue and blacks.
blacks are best and red are crap!
even with black you can see what is "behind" the colour

[quasar]

Such a shame, as all the adds seem so impressive

[logobear]

in the right light, you can always make out the image ....., - but the colour does change - colour change mug !

[quasar]

Had an idea to sell as magic message mugs, picture may be visible both hot and cold, but there will be a message hidden below the blue colour. Works well.

[bms]

Had an idea to sell as magic message mugs, picture may be visible both hot and cold, but there will be a message hidden below the blue colour. Works well.

change the colour of the text then to a lighter grey for instance. This will be hidden beneath the blue until it goes white.

[GoldRapt]

CAll me stupid, but if the text is blue will it not be invisible until the colour changes?