1. Is your "recipe" correct?
Each type of vinyl has its own "recipe" that needs to be applied with. When using HTV Vinyl (Heat Transfer Vinyl), time, temperature and pressure are extremely important factors. Check the instructions of heat transfer vinyl you are using and make sure all settings are correct.
Time-If the ironing time or pressing time is too short, the HTV will not stick to the shirt. Long time pressing or ironing may produce the same effect. HTV works by using heat activated adhesives, so the time is too short and the heat is not enough to stick. Time is too long, it will actually burn off the adhesive.
Temperature - Not all htv vinyls are pressed at the same temperature. Check to make sure you are using the correct temperature. Here, it is really convenient to use a heat press than iron - precisely adjust the temperature and time.
Pressure - Using an iron instead of a heat press usually encounters this problem. It is hard to press down your design with an iron, especially for large designs. You also have to consider what you will lay your shirt on to the press. Take a notice to granite, stones, or surfaces that absorb iron heat. Do not use an ironing board or anything else that will not allow you to get a really firm press with your iron.
Good pressure is when your arms shake from pushing down so hard. You should be able to see the weave of the fabric through the htv vinyl. If you are not sure whether you’re getting enough pressure with your household iron, put more weight behind it.
2. Which fabric do you want to apply the vinyl to?
Check the label on the shirt. What is it made of? Is it nylon? Use heat transfer vinyl for nylon. Spandex ? Will heat transfer vinyl stick to polyester? Can i heat press nylon? Does vinyl stick to burlap? Check out Craft Perfect. Siser Easyweed is usually the winner of cotton, polyester, cotton/polyester blends, burlap, canvas, etc. Just be sure that whether it's the shirt that comes first or the vinyl, they will work together. Our vinyl is not suitable for nylon T-shirts, htv for nylon can be used for nylon hats, belts, etc.
3. Are there thick seams, buttons, zippers or collars?
All these things may be the root of the problem. When the raised area on the shirt takes away from the pressure that actually affects the design, you will lose a lot of pressure. Think this is your problem? Learn how to fix it with a heat press pillow.
4. Are you peeling carriers hot or cold?
This is closely related to the recipe of the vinyl. Some types of HTV may need to be peeled off immediately after pressing or ironing. Others may need to cool down completely before removing the plastic carrier sheet. Incorrect peeling will definitely ruin your craft.
Have you tried all these methods but still cannot make htv vinyl stick? Here are some other things that may cause headaches.
Is your heat press working properly? Sometimes, the heating element in the heat press will go bad, making it unable to heat up the setting of temperature. There may also be hot and cold spots on the entire pressure plate (the plate that gets hot). Purchase a temperature gun to test the accuracy of the heat press.
Is there a waterproof coating on the garment? Waterproof or fireproof coatings can be a big problem. It does not allow htv vinyl to stick to the fibers of the fabric. You can try to remove the coating by rubbing alcohol on the cotton ball where the design is to be applied. There is no promise, but if you are in trouble, please give it a try.
Have you prewashed the shirt with fabric softener? The fabric softener actually sticks between the fibers of the shirt, the same fiber you are trying to make the adhesive or glue stick in. Sometimes this can cause problems htv vinyl adhesion. The best option is not to wash clothes beforehand. If you need a shirt that won’t shrink, buy a preshrunk shirt to prevent it!