Here is what you will need:
Dye Reinkers, Glossy card stock, spray bottle with water and a water brush.
Spray your card stock with the bottle of water.
Need a few drops of several colors of Dye Reinkers. Can put these on your work surface, acrylic block or a pallet.
Take your water brush and swirl the ink around in no certain pattern.
Don't have reinkers. No worries. Here I smooshed several dye ink pads onto my glossy card stock.
Spray it with water.
Sprinkle salt over the whole piece of card stock.
Spray with water lightly.
Now you can heat it with a heat gun or walk away and let it dry on its own.
Now take a paper towel and wipe the salt completely off. It will no longer be glossy.
Here are both of my samples after being cleaned off.
And here are my cards . You can stamp right on this background with no problems.