I'm going to be 'printing' with a baking soda and water solution. I need to apply the solution to a surface that will hold it long enough to lay a piece of paper on it and saturate particular areas of the paper, the letter forms. What is the best surface to use. I've contemplated sponge, but am not sure if the sponge will gather enough solution intact to leave residue of the letter form or whole word on the paper when it dries. I'll find that out by experiment but would love any help that might improve my chances of success. This is for a college typography class.


Well, I've cut the letter forms out of sponge and adhered them to a sheet of Plexiglas. I originally wanted the sponge to sit in the bicarbonate solution and continuously wick it to the top of each sponge letter form. I've done some trials already however on this smaller version I've put the solution on the sponge letters, first with a brush, and recently with an eye dropper. I'm letting the paper dry at the moment.

I'm printing a form of 'Secret Ink'for a graphic design class. If I go with this project I'll have to make 28 posters, minimum 18" x 24" or larger this way.

Thank you all for taking the time to contemplate the problem and come up with solutions.I'll post pics of the results if I can.

  • I am having issues picturing what you are trying to do. Do you have a resource you are trying to follow or a picture of a result you are trying to emulate?
    – Matt
    Commented Feb 11, 2017 at 3:43

3 Answers 3


Are you limited to a mixture of baking soda and water? If you add a thickener (like agar gum) to the mixture to give it a bit more "stickiness," then you should be able to use rubber stamps (or foam cut-outs, etc...just google "DIY rubber stamps" for alternatives). Use a foam brush to apply the liquid mixture to the stamp and apply to your paper.

You will have to experiment with different thickeners (agar gum was just the first one that came to my mind) and amounts to determine what will work best with the baking soda and water mixture.


If I understand the physics of the project you are describing, you want a surface wetted with a baking soda and water solution. You plan to place paper on that surface to transfer the solution to the paper. A sponge of "typical" thickness will likely wick the solution away from the surface.

You should consider a non-permeable surface such as a flat countertop or piece of glass or hard plastic, as long as it is flat enough for your purpose. Place a thin absorbent material on the hard flat surface and soak it with the solution. You'll have to experiment on the quantity of liquid, and you'll want the baking soda to be fully dissolved before applying any.


As a midpoint between sponge and a non-permeable surface, you might consider cork. I think it would remain "wetter" than a sponge while being carve-able, which a harder surface might not be.

Start with a sheet of cork and carve your letter forms as a base-relief, so the letters are raised above the carved away background parts.

Then lightly adhere the cork to one rigid surface and your paper to another. Two flat sheets of wood or metal could serve as these rigid surfaces. The purpose of these rigid sheets is to keep the ink-bearing cork surface and the ink-receiving paper surface completely flat when they come into contact with each other.

From there, it is just a question of painting the raised portions of the cork with your baking soda solution and then "gently" touching the two surfaces together with a minimum of vibration or slippage.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .