you can make solutions of silver nitrate or ammonium iodide in dark rooms and keep them covered so they don't get exposed to light. Then find some stuff that may have radioactive traces in it.(Like a watch dial or some old pieces of FIESTA Pottery (only the red color).
1Break up the pottery into tiny pieces so you hve a lmot a sand like consistency'
2Put doen the sensitized paper (Still covered with a protective sheet so no light eneters)
3Lay some keys or tacks or some other small stuff in a pile an then pour the Fiesta "sand" over top and don't disturb for about a week.
4Your keys an things will take their own "shadow graphs " by gamma radiation
__Do the same with a fresh newspaper (lay some opaguw objects on the paper and let it lay in sunlight for a day or more)
The bisulphite content of the newsprint is alo slightly photo active and the paper will yellow then go lightly brownish) where the light hits it.
An easy art trick is to lay tcks or paper bits on paper and then hit it with spray paint.
This is actually doing airbrush art.
You can mess with the layers , colors , ect and make some really funky art by multiple layers of paint and "masks"
All these techniques can be grouped into either "positive" or"negative" space objsetc.
Where the object itself leaves a deposit of (usually some oxide), that's a positive. Where we uuse the object as a mask and surround it with a color or deposit, that's negative space infilling.