High Flow Medium

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(formerly Airbrush Transparent Extender) 


GOLDEN High Flow Medium is a 100% acrylic binder system that is designed to modify GOLDEN Airbrush Colors and High Flow Acrylics for increased transparency and film hardness. Engineered to meet the highest standards of professional airbrush illustrators, High Flow Medium possesses excellent spraying properties and is formulated to minimize tip build-up, clogging and surface defects.


Mixing Directions

High Flow Medium can be blended with GOLDEN Airbrush Colors or High Flow Acrylics in any ratio desired, allowing artists to precisely control of the transparency of the colors. These attributes are very important for techniques such as shading and smooth gradations.

High Flow Medium can also be used with any of the GOLDEN Heavy Body, Fluid, High Load, and Iridescent & Interference Acrylics. When the mixture of Paint and Airbrush Medium exceeds a ratio of 1:2 or more, High Flow Medium can be added to further thin and extend. This will keep the retarder level balanced for a quicker drying film, without sacrificing sprayability . GOLDEN Airbrush Medium is useful to make products spray better, but it can quickly over-compensate the amount of needed retarding agents. Such an overload will hurt the drying and increase the likelihood of Frisket1 pull-up (see below).

Blending Suggestions

Stir gently to ensure homogeneity before blending with GOLDEN Airbrush Colors or High Flow Acrylics. Also mix Airbrush Colors and High Flow Acrylics according to label directions before blending with High Flow Medium. Any ratio of High Flow Medium to Airbrush Color or High Flow Acrylics can be used. Generally, a ratio of 5 to 10 parts High Flow Medium to 1 part (by volume) Color is a useful starting point to yield adequate transparency. Careful blending is required to minimize foam generation, as excessive shaking or stirring readily entraps air bubbles which may result in surface defects.

Water can also be used with High Flow Medium and the Airbrush Colors or High Flow Acrylics, but doing so will reduce the sprayability and frisket performance that High Flow Medium enhances. When using water with High Flow Medium, a 1:2 ratio of water to High Flow Medium is the maximum amount of water recommended.  Note: Dilutions beyond the 1:2 mixture will increase the haziness of the dried film as the binder is further extended. If a more dilute mixture is needed, we recommend testing before application to a painting surface. 

Spraying Iridescent and Interference Colors

Beyond the Iridescent paints offered in GOLDEN High Flow Acrylics, GOLDEN also has a broader range of both Iridescent and Interference colors in Fluids and Heavy Body, and both of these can be reduced with High Flow Medium for spray-applications. Generally, the Airbrush Medium is recommended for reducing Fluid Acrylics, however, testing has shown the reflectance to be higher when High Flow Medium is used instead. The lower level of retarders in the Medium will allow for faster drying times when spraying larger areas with an even film.

Frisketing/Masking Techniques

When frisketing is of critical importance, GOLDEN High Flow Medium should be used to extend the Airbrush Colors and High Flow Acrylics. This combination dries more quickly, friskets extremely well, and has excellent spray performance. GOLDEN Airbrush Medium also functions as an extender for Airbrush Colors and High Flow Acrylics for applications requiring greater transparency and greater open time (slower drying). Because of the slower drying, using the Airbrush Medium with the Airbrush Colors or High Flow Acrylics may result in poor frisket performance (color pulling up with the frisket or mask), unless the film is completely allowed to dry.

Drying Recommendations

When frisketing or working with loose masks, allow adequate time for the paint film to dry and refrain from using excessive force during frisket application. Generally, a 10-minute drying time is recommended; however, this time can change dramatically in relation to climatic conditions. High humidity (greater than 80% RH) and/or low temperatures (less than 60oF) will slow the drying process. Low humidity (less than 40% RH) and/or high temperatures (greater than 80oF) will speed the drying process.

Use of a hair dryer or heat lamp can be used to shorten drying times, but exercise caution as excessive heat can warp the illustration board, and/or create air bubbles under any frisket in place, or interfere with film formation and yield a fragile film.

General Information

Paint on any non-oily surface. Non-absorbent surfaces should be abraded for increased adhesion. Clean tools with soap and water. Keep tools wet during use. Do not allow the product to dry in airbrush. Clean airbrush with water, ammonia/water, alcohol or miscellaneous household cleaners (however, consider the effect  of cleaner on airbrush parts, such as rings and seals).

Note: dilutions beyond the 2:1 mixture (Medium to Water) will increase the haziness of the dried film as the binder is further extended. If a more dilute mixture is needed, we recommend testing before application to a painting surface. 

Further Reading


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.