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How to Heat-Set Fastex
Textile Painting Ink

Fastex - Paint your own t-shirt set

Why heat setting is important

Why do you need to heat-set Fastex:

Heating sets fabric ink for durability, colour fastness, prevention of smudging, and enhanced adhesion to the fabric. It activates heat-setting agents and accelerates drying, ensuring a permanent bond with the fabric.

Curing the Ink:

Fabric inks often contain pigments or dyes that require proper curing to adhere permanently to the fabric. Heat setting initiates this curing process, ensuring the ink becomes an integral part of the fabric fibers.


Heat setting significantly improves the durability and wash-fastness of the fabric ink. It helps the ink withstand repeated washing and wear, preventing it from fading or washing out over time.

Colour Fastness:

The application of heat enhances the colour fastness of the fabric ink, making the colors more resistant to fading or bleeding. This is particularly important for preserving the vibrancy and integrity of the printed design.

Preventing Smudging:

Heat setting helps prevent smudging or transferring of the ink onto other surfaces. It locks the ink into the fabric, reducing the risk of unintentional smears or stains.

Enhancing Adhesion:

Heating the fabric ink promotes better adhesion between the ink and the fabric. This adhesion is essential for preventing the ink from cracking or peeling over time.

How to Heat-Set FAS Fastex Fabric Painting Ink

What makes Fastex so durable is the heat setting.

All fabrics that can been ironed at a good hot setting suitable to the fabric can be painted on.  

​The heat setting fuses the ink and the fabric fibres together to make a lasting durable finish. ​

Fastex HD Textile Inks need to be heat set if they're painted on something that's going to be washed.

  • Allow the garment to dry thoroughly before attempting to heat set.   

  • Always iron with a dry press setting. Do not steam iron. Your iron should be set at the highest setting allowed for the decorated fabric.

  • Protect the ironing board with a paper towel or some waste fabric as during curing some pigment staining may occur. For t-shirts, place a paper towel or waste fabric inside the shirt.

  • Heat set with a household iron at medium setting for 3 to 5 minutes on each side.  The process is the similar as ironing a garment, except you'll iron an area for longer than you would to iron out creases.  It is all about heating the fabric to fuse the ink inside the fibre.

  • Iron slowly but be sure to keep the iron moving at all time so there is not damage to the fabric design.

See the video below for more information.

Create & paint your own t-shirt

Insert Card inot the t-shirt

Place card inside your T-shirt

Paint your t-shirt with Fastex

Paint your design

Heatset your t-shirt

Once dry, heatset the ink

t-shirt Painted with fastex

Wear It!

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