acrylic mediums and other mysteries

Acrylic mediums

I’ve put these pages together to help clear some confusions for fiber artists and people exploring mixed media.

My background is in painting and acrylics have been  a favorite medium for decades. The better companies are always improving and expanding their product lines and the field has changed a lot over the years.

Fiber artists are using various paints and mediums with fabulous results but some people need/ want more information.

This is not intended to be a comprehensive or authoritative text,  just some definitions, explanations and general guidelines.

For more specific and technical information, visit the manufacturers websites. Most of them have good resources. Some of them will answer specific questions.

Experiment, play, test. have fun!

The words:

Medium – In general art terms “Medium” refers to a category of art, i.e. “painting”, or the type of painting (water color, oils, acrylics), photography, sculpture, clay, glass, fiber, etc.

The plural of medium is media. Artist who combine art forms often refer to their work as “mixed media”.

To further confuse things, “multi-media” usually means art that goes across categories. Multi-media art might include video or dance or performance of any sort in combination with static forms such as sculpture or painting.

For our purposes, “Medium” (plural: mediums) is the substance that binds the pigment in paints. In acrylic paint this is the polymer. All acrylic paints include medium in their formulation. Additionally, mediums are packaged separately. There is a fascinating, and confusing array available.

Acrylic mediums are an emulsion of polymer and water and may be used to change the paint, to coat a substrate, to protect a surface, used as adhesives and more. They may be tinted or used from the container.

Binder – in acrylic paints, the binder is the chain of polymer molecules. They hold the pigments in place.

Pigment – a dry material, may be organic or non-organic, synthetic or natural. Some pigments are lightfast, others are considered fugitive. Pigments are mixed with binders to created paints, colored pencils, pastels or chalks. High quality paints have a heavier pigment load than student grade paints.

Emulsion – the mix of acrylic polymer and water. As the water dries or is absorbed by the sub strata, the polymers adhere to each other, trapping the pigment if there is any and creating the acrylic film.

Vehicle is the liquid portion of a paint or medium. In acrylics, this is water.

Substrate is the surface to be painted.

Gesso is used to seal the substrate. This is essential for oil paints, not necessary with acrylics. If the artist working with acrylic paint wants a toothy or non-absorbent surface, gesso may be applied; fluid medium may be used instead.

Gesso comes in white, black and clear. The white and clear may be tinted with paint.

The Stuff:

All acrylic products may be combined across types and across brands. There are few absolutes.

A good understanding of how things work will help with decision making.

Fluid Mediums are liquid in nature. They increase viscosity of heavier paints and gels, tend to self-level and do not retain brush strokes. They help maintain or enhance adhesion and durability.


•Increase flow of acrylic paints

•Dry transparent or translucent, may be used to seal a surface, may be mixed with water to seal water soluble pencils or paint sticks onto fabric.

Some artists are applying dry colored pencil or chalks to fabric, Sealing with medium (of any kind) may help preserve the surface and prevent the color from rubbing off.  Test first! Effectiveness of this application may be compromised by factors such as sizing in the fabric, other materials used and unknowns.

I recommend coating the surface to be altered with a thin dilution of medium and water. Allow it to dry, then go in with your dry materials. Apply another coat of medium on top to seal.

•Fluid mediums make an excellent archival adhesive for collage on surfaces that can handle moisture. Gel mediums are more versatile as adhesives.

•For best results, always test before using

•Mediums extend the volume of paint. Mix Mediums into acrylic color to add flexibility, increase adhesion, and long-term stability. Mediums can add or subtract sheen from a surface and can create transparency.

•A thin film (1/16”) of medium may take between 1⁄2 hour to 24 hours to dry, while a thicker film (1/4”) may take between 2-5 days to dry. Much depends on the environment, climate, application notwithstanding.

•A humid environment will slow the drying time of all Mediums, dry warm air can speed drying time. Some artists use hair dryers to help the process.

•Oily, oil painted, greasy or waxy surfaces can repel acrylic films.

•Do  not  overwork mediums during application. If mediums are over-brushed during drying, clouding may result. Once the acrylic film is clouded and dry, it cannot be clarified or removed.

Heavier mediums, such as heavy body gels, may need a stiff brush to push the medium into the surface.

Airbrush Medium thins acrylics to a consistency that allows spraying without affecting flexibility, durability, or adhesion.

This ready to use, pre-mixed blend of acrylic emulsion, water, retarder, and Flow-Aid can be mixed with all acrylic paint, acrylic inks, mediums, and gesso.
Finishes/ sheen: All mediums, whether fluid, or gel, in any of the weights, are available in matte or gloss finishes. Some product lines have intermediate finishes. All mediums may be combined, may be used with all acrylic paints, inks, or used alone as adhesives, glazes or to stabilize other products on a surface.

Drying Time: An acrylic film surface will feel dry to the touch. Except when blending, allow the film to dry before applying additional layers.

Open Time is the time during which acrylic paints are moist and workable. The use of additives can extend this: mediums, extender, or flow release. Water will also extend the open time, but weakens the paint film and pigment load.

Curing Time, This is the time span required for the acrylic film to reach its maximum stability and durability. When cured it is less vulnerable to solvents and other factors. The amount of time a surface takes to cure depends on factors such as thickness of application, the ambient humidity, the absorbency of the substrate and the amount of moisture in the environment.

Generally speaking, allowing a painted fabric item to dry/age/cure for a minimum of three days before heat setting is recommended. It is best to allow at least a week before laundering.

Cleaning/laundry/abrasion – Painted fabrics should be heat set and allowed to “cure” for a minimum of a week before any laundering.

Wash gently, using soap that does not include “whitening agents” or bleach.

Air-dry painted fabrics, do not dry mechanically. Dryer Lint is created through abrasion. Since acrylic paint sits on the fibers instead of permeating the fiber as a dye does, the paint is subject to abrasion. This will cause loss of color. Of course, Murphy’s Law often comes into play: If you want to lose the color (from your favorite shirt for example) you will not be able to. OTOH, wanting to keep the color and painted effects requires diligence.

Sewing through – much depends on the variables: how thick is the application of the acrylic product? How many different products are used?
Generally speaking, if a thin application of paint/medium is applied to cloth it can be easily needled. My recommendation is a 90/14 needle, or, for surfaces with a heavy hand, a 90/14 Microtex needle or a Jeans needle. Another artist I know coats all his work with two layers of medium and has no trouble stitching with a Universal needle. He cautions that the coated surface must be completely dry before stitching.

The gel mediums create a heavy surface and again, in my opinion, are better used after stitching has been finished. Impasto surfaces, molding paste and heavy texture gels may not be suitable for flexible surfaces. They are subject to cracking and may not needle well. Test!

Fabric medium/ Textile medium
This fluid medium enhances the workability of acrylic paint on fabric. It controls bleeding of colors thinned with water and provides a smooth, consistent flow to acrylic color.

Fabric Medium also prevents uneven application of paint to rough fabrics. It reduces the stiffness of dried acrylic paint on fabric and allows paint to penetrate the surface, yet maintains fabric hand.

Please note: the paint will still be subject to abrasion, it is not absorbed into the fiber as dyes are.

These mediums are recommended for wearables that are to be painted. For cloth that will not be worn/washed, regular fluid mediums may be sufficient. Fluid mediums can be used in combination with paints across all product lines to create painted cloth, and to alter commercial fabrics. The degree of dilution with water is a personal preference. There are no formulas. The hand of the fabric, drying time, and “stitchability” will be a result of the proportions of paint, medium and water.

As far as I know, all fabric/textile paints are acrylic products. They have different effects depending on their composition. All are combinable.

Glazing Medium creates brilliant, jewel-like glazes when used with acrylic colors. It has excellent brushing and leveling qualities and it dries quickly for rapid layering.

This medium works best with transparent or translucent colors. It is flexible, non-yellowing, non-cracking, and water resistant when dry.

Pearlescent tinting medium is a soft body medium that produces a range of iridescent colors when mixed with acrylics paints. It is opaque when wet, transparent to translucent when dry and is great for creating metallic effects that won’t oxidize. It also makes a nice glaze on top of other surfaces.

Extender medium is a soft body medium. It increases the volume of acrylics without affecting opacity or hue.

UV Protection For UV protection of acrylic paintings, the use of an acrylic varnish is needed. These varnishes are available for flexible and non-flexible surfaces. I have used UV Acrylic Varnish on stitched surfaces. It is necessary to apply a layer of fluid or gel medium first and allow the surface to dry completely before applying varnish. The end surface will not be soft, but will retain the look and texture that existed before varnishing.

Gel Mediums add body to thinner paint for impasto techniques as well as extending color volume and adding transparency.  Gels also add “open time” as they tend to dry slower than thinner paint films. These mediums tend to improve adhesion and durability of the paint film. They are translucent when wet and transparent when dry. They dry to a gloss finish.

Gloss Gel can also be used as a transparent ground for acrylic paint and makes an excellent adhesive for mixed media collage.

Gels come in different weights and finishes.

They may be applied with brush or knife.

Texture Gels contain particles that produce a variety of unique textural and dimensional effects. They may be mixed with acrylic colors, other mediums, or used on their own. Dry Texture Gels can be over-painted with acrylic or oil colors and can be used as an under painting textural ground. They may be combined to achieve unique surfaces.

Modeling paste is an extra heavy body, very opaque modeling paste for oil and acrylic colors. Made from marble dust and polymer emulsion, it’s perfect for building heavy textures on rigid supports and for creating three-dimensional forms.