So what we need is some gel medium, a brush, a printed photo and a surface to put it onto.
So you coat the front of the printed photo with the gel medium and then turn it over and adhere it to your chosen paper/background/canvas etc.
Leave to dry.
When completely dry spray the paper with water using a mister bottle.
Start to gentle rub the paper backing off with your finger.
Keep rubbing until all the backing paper has been removed and then leave to dry.