Start by painting your coasters. I used two coats of white chalk paint on all surfaces (top, bottom, and sides). Be sure to allow to dry in between coats and also before continuing with the tutorial.
In the meantime, you can print your images onto your printable tattoo paper. I did mine in black and white. Be sure to mirror your images before printing so they will be the correct orientation when transferred to the coasters.
Follow any instructions that comes with your tattoo paper. For this packet, you peel back the liner on the adhesive and put it on top of your printed images. I pressed it down really well using a stir stick like a squeegee.
Trace the coasters with a pencil on top of the images. Cut out with scissors.
Now just peel away the clear liner to expose the adhesive. Turn the image over with the adhesive down and place it on your painted coaster. Press down really well. Again I used a stir stick like a squeegee to ensure complete adhesion.
Then use a damp rag on top of the paper that is covering your image. Do not rub. Just press with the wet rag. Eventually the paper will start to lift from the image. Remove the paper and you are left with a gorgeous image on your coaster.
Seal the coasters with two coats of decoupage medium. Apply one horizontally and one vertically allowing to dry in between coats. Allow to dry.