I did a class on this years ago. They called it decoupage. You painted a papier mache box with emulsion, let it dry, stuck any old picture you liked on & then brushed on PVA glue over the whole of the top of the box , keep brushing on layers of PVA letting it dry thoroughly in between coats until the design looks completely flat and part of the box - I didn't explain that very well but hopefully you know what I mean - I can't remember if the PVA was watered down. You also need to keep it covered while drying as any dust/tiny hairs will stick & spoil the effect.