Today I have been experimenting with some scrap thermal till rolls from work. I started off by placing objects onto the till roll and heating with a heat gun. The items included: Sellotape and drawing pins, paper clips, staples and scissors.
The results were exciting if a little haphazard with surreal, dreamlike images appearing.
I then tried blowing hot air through a stencil, this was not terribly successful as the hot air warmed the surrounding area and made the mark indistinct. More successful was sticking blue tack to the paper to create a mask then heating.
As I stuck the samples into my sketchbook I noticed that something odd was happening; the glue was reacting with the paper. This was a surprising development as I had not expected it but I then decided to see what happened if I used the glue on the front and then the back of the paper.
Using Uhu on the back of the paper gave a controllable black mark, on the front; a tramline effect enabling some great mark making opportunities.
I would also like to try spraying hairspray onto the paper as after discussing my experiments with fellow students via the OCA Facebook pages, it has been suggested that that reacts as well.
Further developments would be to try pressing heated objects on to the thermal paper or leaving items on top of the paper and leaving in the sun to see what a lower heat will achieve.