HEAT CURING TIPS
How much heat and time is needed to cure the product depends on how big the graphic is and how much ink you are laying down. For SI silicone ink that we offer at lnkcups, we recommend starting with six minutes at 124 degrees C (255 degrees F). Some customers will be able to use a little less heat and time – but you will need to test your particular product and image internally. In my experience, wristbands require less heat/time and swim caps, more. If your product is coming out of the oven and the ink is smudging off, it needs more heat and/or time. When cured properly, the ink becomes an integral part of the product.
You want to aim at the lowest heat and shortest time that does the job, not only for productivity reasons but also to avoid exposure to formaldehyde, which would pose health risks. Liquid silicone starts producing formaldehyde when heated to a certain temperature. For our SI inks, it is 149 degrees C (300 degrees F). It is crucial that you ask your silicone ink provider what that temperature is for their ink formulation.
If you are not sure if your product is actually made out of 100% silicone watch the video: Silicone Printing: How to Test if your Product is actually Silicone.