First, I'd like to describe an effect I am trying to achieve. Then I'd like to pose several questions that have been developed from initial discussions.
A piece of card-stock. One side contains some text, printed normally. The other side, however, has a sticker which is a picture (full color, opaque). The back of the card (beneath the sticker, revealed when the sticker is pulled away) has text, printed normally. When the sticker is peeled away, the picture on the sticker ceases to be visible (either becomes utterly garbled in a seemingly random fashion, not simply an obviously correlated color mutation, or else becomes monochromatic or clear).
Additionally, the back of the card has text that is glow-in-the-dark and thus only appears in the dark. Preferably, the intensity or rate of fading of the glow-in-the-dark text would be variable by word so that different words would remain brighter/more visible for longer or would become visible sooner or more clearly in the dark). However, while preferable, this part seems a logistical nightmare and could be skipped with minimal loss to the piece's integrity.
The back also contains text which is revealed beneath some temperature and text which is revealed above a certain temperature. Both these kinds of text should vanish when the temperature reverts back above or below the threshold temperature.
That's the general idea. Now, the first idea is to use acid-base indicators contained either on the back of the card or on the back of the sticker, effectively sealed in by the sticker, to provide the color picture. When exposed to air, their pH values would change and either they would become clear or garbled. However, it is unclear 1) what variety of color could be achieved, 2) how they would be applied, particularly without contaminating them before they are 'sealed' to provide the initial color, 3) what chemicals would be necessary if it could be achieved. The questions are thus, "what?," "how?," and again "what?"
Another idea, for the vanishing picture portion, is to use some kind of plastic film that can polarize light and that, as a separate but necessary point, would "break" or become unusable once remove so it could not simply be reapplied to view the picture again. The questions here are essentially "can light be so polarized as to reveal a colored image and then to reveal total noise or nothing at all when the polarizing filter is removed?"
As general questions, how exactly to achieve the heat-transitioning text effects is appreciated, though it seems a simpler prospect as the text colors can be uniform for each "effect" (normal text one color, cold text one color, hot text one color), unlike the picture, which should be in full color if possible. Additionally, any insight on the glow-in-the-dark matter is welcome.
And further, and yet perhaps the most important question, "can these effects be combined without interfering with one another?" Worth noting, the separate text effects would be placed separately so as not to interfere with one another, but if the picture creates a problem or if the chemicals behave poorly with the conditions of the other effects (for instance, becoming deactivated), that would be an obvious problem.
In advance, thank anyone for any suggestions. I recognize this is a fairly specific set of questions.
