* Polymer Clay: Small amounts of several pastel colors. Here's the formulas I used to match the colors of the Necco brand candy hearts. (White refers to a 2:1 mix of Premo white and UltraLight; all other colors are by Premo.)
Yellow heart: 1 part Cadmium Yellow; 4 parts white
Orange heart: 1 part Orange; 7 parts white
Green heart: 1 part Green; 7 parts white
Pink heart: 1 part Fuchsia; 1/4 part Cadmium Yellow; 5 parts white
Purple heart: 1 part Purple; 1/2 part UltraMarine Blue; 6 parts white
* Tools: Scissors, needle tool or toothpick, stiff-bristled paintbrush, clay knife
* Color laser printer or color copier
* Rubbing alcohol
* Corn starch or baby powder
* Candy heart (optional)
* Amazing Mold Putty (optional)
Step 1: Make a Candy Heart Mold (Optional)
Allow the mold to set. Once it's ready, press a 1/4 teaspoon ball of clay into the mold. Use a scraper tool or a clay knife to remove excess clay from the back. Pop the heart out and correct any molding flaws.
If you don't want to make a mold, you can easily hand-form the heart based on a real candy heart (or a photo of one).
Step 2: Print the Message to Transfer
If you're creating your own transfers, I recommend using the "Stamp Act" font, 8 pt size, with kerning set to 1.5 pt -- you can get this font free from Harold's Fonts. If you're doing your own, be sure to select mirror image on your printer's settings before you print.
Step 3: Apply Transfer to Clay
Step 4: Brush on Rubbing Alcohol
If you prefer, you can leave the transfer sitting overnight instead of using rubbing alcohol.
Step 5: Add Powder
Step 6: Trace Letters
Brush the transfer lightly with rubbing alcohol once more. You should be able to see the letters through the paper. Use a toothpick or needle tool to trace the letters, creating an indentation in the clay. This step often makes it easier to remove the paper as well: as you're tracing the letters, you may see an edge start to stick up. Once you're done tracing, use tweezers or a needle tool to coax the paper up the rest of the way. Your message should be transferred onto the clay.
Be careful not to touch the transferred letters, as the ink is still wet and will easily smear. If you're not in a big hurry, I'd encourage you to let this sit a few hours til the ink dries. That'll help prevent smearing. But if you're in a hurry, continue on and just be really careful not to touch the ink.
Step 7: Touch Up & Bake
Once you're happy with the heart, cure it in the oven according to the clay manufacturer's recommended time and temperature.