GAC 900 Heat-set Fabric Painting Medium – For Wearable Fabrics

GAC 900 Heat-set Fabric Painting Medium – For Wearable Fabrics

GOLDEN GAC 900 is a liquid acrylic medium that is blended with artist acrylics to create fabric paints intended to be applied to fabrics, textiles, and garments that need to hold up to repeated laundering cycles.


GAC 900 is designed to be blended with standard artist acrylic paints, such as GOLDEN Heavy Body Acrylics. Start at a 1:1 mixing ratio of paint to GAC 900, and adjust as needed to modify the consistency for the type of paint application you intend to do. The amount of GAC 900 may also be increased to improve softness of hand (such as when working on delicate fabrics.

Apply the paints as desired and allow the paint to dry well before heat-setting. Heat-setting is necessary to fuse the GAC 900 into the fabric and improve the “hand” or softness of the laundered garment. Properly heatset the painted areas by following the below temperature and duration recommendations. The temperature setting and heating duration impact how well the paints will remain in the garment during repeated wash/dry cycles.


The ideal GOLDEN paint lines for use with GAC 900 are the High Flow Acrylics, Fluid Acrylics, and Heavy Body. The main difference between each of these lines of acrylic colors is viscosity (thickness) or consistency. These various acrylic paint lines, each using the same lightfast pigments, allow the artist to combine the effects of spraying, staining, brushing, and other application techniques. Other GOLDEN Paints and brands may be used with GAC 900 but test performance before use on actual projects.

  • Heavy Body Acrylics have a thick, buttery consistency. Heavy Body are best for crisp edges and detailed brush painting.
  • Fluid Colors are similar in consistency to heavy cream. Fluid Acrylics are best for thin brushing and airbrush applications.
  • High Flow Acrylic Colors are thin, ink-like paints. They work best for staining or dyeing techniques.

Start by mixing the paints with GAC 900 at a 1:1 ratio. You can adjust this amount depending on the kind of fabric, paints used, and desired technique. Note that higher percentages of GAC 900 will make the mixtures very thin and also increase the tackiness. Mixtures can be stored for several weeks in a sealed container.

Apply the paint mixtures as desired and allow them to become completely dry (air dry time can vary between 1 and 4 hours for most applications, but longer times are usually preferred when practical), then heat-set the garment as per the instructions below.


Hand Brushing - Filling in large areas with thick paint will produce a very stiff, uncomfortable garment. Blend color with GAC 900 to reduce the stiffness of the acrylic paint. If painting thickly, short strokes of paint will hold better than long lines. The longer the line, the greater the chance of cracking when washed. A washing machine’s agitator may stretch the garment beyond its limit and thus cause cracking.


Fluid Acrylics can be mixed 1:1 with either GOLDEN Airbrush Medium or GAC 900. GAC 900 has a tendency to become sticky inside an airbrush, resulting in more frequent cleaning of the needle and nozzle, so it can be tedious for highly detailed work, however, spraying GAC 900 as a base layer or topcoat works well.


The viscosity of GOLDEN High Flow Acrylics is ideal for tie-dye and staining applications. However, the binder used is harder than the other paint lines and therefore color washes out more than when using Fluid and Heavy Body Acrylics.

A 1:1 ratio of GAC 900 and paint helps improve the stain penetration, fabric softness and launderability. Pre-wetting the fabric with water, followed by wringing out the excess water, helps the paints penetrate into the fabric and creates a more “Tie-Dye” effect. If the fabric has been folded into a pattern (such as a spiral), allow the fabric to partially dry, then carefully remove the strings/rubber bands, but do not completely open up the fabric. If the fabric is still very wet, the colors will merge and the pattern will be less distinct.


GOLDEN Heavy Body blended 1:1 with GAC 900 creates silk-screen inks for wearable fabrics. The mixture used is dependent on two factors: the material to be printed and personal preference of paint consistency. Fluid Acrylics and other paints lines can be used, but they tend to become too thin of a consistency which can “bleed” more readily after printing.


It is important to properly heat-set garments that have been coated with GAC 900 or paint mixtures containing GAC 900. ALWAYS TEST TO BE SURE THE DESIRED TEMPERATURE AND DURATION DO NOT RUIN THE FABRIC OR THE PAINTED SECTIONS.

Temperature & Duration: The amount of time necessary to properly heat-set GAC 900-painted fabrics is based on the device temperature setting and the duration of time the heat is applied to the garment. Hotter temperatures heat-set faster, but lower temperatures may be necessary with certain fabrics.

Proper Ventilation Necessary: Heat-setting GAC 900 releases low levels of formaldehyde; therefore, adequate ventilation is recommended when heat setting. For example, if you heat-set using your home clothes dryer, the air is vented outside during the heat-setting process. When using a clothes iron or a heat press, work in an open room near a fan exhausting air outside and have a fresh air source to ensure positive airflow.

Heat-Setting Devices

Clothes irons, clothes dryers, and heat-presses may be used to heat-set a garment painted with GAC 900. The heat-setting device’s temperature range to heat-set may not be ideal for the type of fabric and/or the acrylic products painted upon the specific fabric type.

Note: Using home dryers and irons to heat-set painted designs is a different purpose than they were intended to be used for. Take proper precautions and avoid scorching the paints or fabrics.

  • Residential Clothes Dryers achieve a maximum temperature of 135°F (high setting), and you can heat-set multiple pieces at once. Place the garments in the dryer on high for around 40 minutes.
  • Laundromat (commercial) Clothes Dryers can potentially reach temperatures up to 176°F (high setting). Place garments inside for about 20 minutes depending upon how hot the dryer is getting (not all commercial dryers achieve the same temperature, even the same models).
  • Clothes Iron can reach around 440°F and many will heat unevenly. Use the appropriate temperature that will heat-set but not scorch the fabric.
  • Heat-Presses can reach over 450°F and are adjustable to a precise temperature and duration. Because of this, you can set the temperature at 390°F, and press for 10 seconds, but lower temperature reduces the chance of scorching the paints and discoloring or warping fabrics.
Starting Point Settings Based on Fabric Type

Fabric Types

Setting (Temperature)


Delicate Synthetic Fabrics

(i.e., Nylon, Lycra, Spandex, Acrylic)

Low (110°C/230°F)

3-5 minutes

Moderately Heat-Sensitive Fabrics

(i.e., Silk, Polyester, Wool)

Medium (150°C/302°F)


1-2 minutes

Temperature-Resistant Fabrics

(i.e., Rayon, Cotton, Leather)

High (200°C/392°F)


15-30 seconds


Textile/Material Considerations

Test fabric materials and paint mixtures thoroughly before any large production runs or when using a unique fabric. The looser the weave of the fabric (cotton/poly blends), the better the penetration and hold the paint will have on the material. Thicker fabrics (sweatshirt-type weaves) should be slightly stretched with a backer-board to allow for better penetration of the paint into the material.

To improve adhesion, a very light misting of water (e.g.-with a plant-mister) increases paint penetration into the fabric material. Care should be taken with this technique, as over-applying the water could result in bleeding of the color. Before attempting heat-setting, be sure to identify the type of fabric and the maximum temperature it can endure. For example, 100% cotton fabrics can endure hotter temperatures than polyester or silk fabrics.

Post Heat-setting Washing and Drying Suggestions

  • Hand-painted garments will last longer when care is taken during washing and drying.
  • Provide care instructions to the wearer to help improve the lifespan of the painted garment.
  • Hand-washing/hand-drying (drip-dry) dramatically increases the painted design.
  • When possible, turn garments inside-out for laundering.
  • Avoid hot water washing. This can soften and loosen acrylic paint from the garment.
  • Cold water works best for automatic washing of the painted garment.
  • Set clothes washer to gentle/delicate cycles.
  • Don’t wash garments with coarse garments, such as blue jeans.


The above information is based on research and testing done by Golden Artist Colors, Inc., and is provided as a basis for understanding the potential uses of the products mentioned. Due to the numerous variables in methods, materials and conditions of producing art, Golden Artist Colors, Inc. cannot be sure the product will be right for you. Therefore, we urge product users to test each application to ensure all individual project requirements are met. While we believe the above information is accurate, WE MAKE NO EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, and we shall in no event be liable for any damages (indirect, consequential, or otherwise) that may occur as a result of a product application.