free 3d sheets for making cards?

Answer 1

It used to be done from picture postcards, try a store that sells cheap cards and ask for their damaged stock.
Try to get several issues of the same (free or old) magazine and use pictures in there.
Print a picture from internet or your own photos several times on heavy paper, (carefull if you have an ink-jet printer because that ink will run when it gets wet.)
Have a good look at internet 3d sheets and draw your own, copy and colour for the different layers.