How to Make your Own Polymer Stamps

Step 5 Exposing the Image

With this preparation done you can now proceed with the exposure process. Pour liquid photopolymer gently onto the negative, filling the space up to the level of the damming tape. If there are any bubbles, quickly but careful pop them with a needle tool. Place the substrate, frosted side down, on the photopolymer, making sure there are no bubbles trapped under it or the stamp will peel off later. Place the other side of the glass unit on, making sure the magnets take hold. You may notice some seepage from the edges of the negative as the glass compresses. This is normal.
Place the unit centered under the light, substrate side up, and set the timer for approx. 1 minute 30 seconds. (exact developing times will vary from light to light, experiment on some smaller stamps to get the exact times dialed in for you). Turn on the light and develop for the required time. This develops the backing of the stamp. Turn the unit over and develop for the same amount of time on the other side, and turn off the light.