[fishmittens]

I am doing an art project in which i need some kind of substance or paper that once touched (lightly would work best) it leaves some kind of mark.
Even a liquid which i could secretly place elsewhere and when touched and depostied elsewhere leaves a mark.

I am flexible as to what material i use but it would be awesome if it could look pretty or interesting.

Any help will be greatly appreciated!

xxxx

[Biopolmonkey]

Do you mean touched by fingers, or just by something/anything?

First thing that springs to mind are indicators - things like litmus paper, universal indicator (paper and liquid) etc. These require acids and/or bases to change colour - you can use things like lemon juice, vinegar, soap.

[fishmittens]

yeh i have tried the litmus papers.

basically what i am doing is a cupboard with this special paper or material inside which seems to absorb something when touched by fingers.

I thought i could put some acids and alkalines on the cupboard handle so that the person touches these and then touches the paper it would leave a mark. but unfortunately this doesnt work so well and it also fades after a while.

is there anything that might make a stronger reaction and possibly permanent?

i even thought about doing the hot ice that changes from liquid when touched but not sure how i could make lots lots and lots of them as lots of people will be opening the cupboard and they will alll need to get a reaction.

thanks for replying x

[fishmittens]

oh and it doesnt necessarily need to be their fingers i guess, if there is anything else?

[Mesogen]

How about a sheet of thermochromic liquid crystal? It starts as black usually and goes through red to blue with increasing temperature (i.e. when touched).

[fishmittens]

That is almost perfect but i would love if the effect could have staying power.

It doesnt have to be pretty , it could look eerie and ugly.

It could be some sort of imprint.

Aargh i am getting desperate!