Golden have the widest range of mediums for acrylic paint, including gels, additives and effect pastes. This means you can have whatever qualities you desire for your acrylic painting: luminous glazes, gritty opaque structures, string effects, glassy areas and also, variable drying times. Understanding which acrylic medium is right for your required working qualities can be tricky, so we’ve tested out all the main mediums for you. This expansive range gives rise to inspiring possibilities, that will allow you to do very unusual things.
Which Acrylic Medium Should I Use?
Acrylic paint is one of the most versatile paints, it can be formulated with a vast range of consistencies and qualities and easily adapted with mediums. This means it can be used with techniques similar to those used with watercolour washes, impasto oil, pouring inks or even gouache, depending on the acrylic and mediums you select. The qualities that make it similar to other mediums can all be incorporated into a single painting, whether you want to use it thick like oil using it’s increased flexibility, or create thin washes like watercolour that dry waterproof and can be worked over without worry. It has the amazing ability to be layered in a myriad of ways, very quickly, if you desire to make use of its fast drying time.
Qualities that mediums can modify are texture, sheen, thickness, drying time, hardness and viscosity. Goldens mediums can be broken into several groups, each of which, modifies different characteristics of the acrylic paint and has unique applications. These groups change a few characteristics each.
Gels tend to be transparent and increase body, those gels with aggregates have bits in them to change the texture and to produce unique textural effects.
Pumice gels use sand and gritty concrete-like solids in a transparent binder to create texture, meaning their ability to create peaks is decreased slightly and their opacity is slightly increased.
Molding pastes increase body but are almost completely opaque and some have additives to give them unique textural effects.
Clear Tar Gel, Leveling Gel and Glazing Liquid affect paint’s viscosity, flow and drying time, but all are levelling, smooth and transparent.
Golden additives such as retarder, open thinner and wetting agent affect how the paint dries, decreasing surface tension, maintaining or slowing drying times.
The 7 GAC mediums are the most fluid of all the mediums and change the hardness, film flexibility and adhesion of acrylic paint.
Most mediums are available in gloss, matt or semi-matt and you can use a varnish over a finished acrylic painting to unify the finish whether you want a matt, gloss or semi-gloss surface. This is why we chose not to look at sheen for this comparison.
When colour-concentration is of key importance in your work, you should use as little medium as possible, and start with a paint which is closest to your required consistency. While it is possible to mix consistencies, like using a heavy body medium with a soft body acrylic, more medium will be required and as a result, the colour will be less strong. Equally, If you wish to thin your acrylics but keep the intensity of colour, it’s best to start with a thinner paint and add a little fluid medium to extend it further.
I found when we tested these mediums that within two days all of them were touch dry and after a week they all were hard but dentable with a nail, however, during the testing period, the temperature was over 22 degrees.
Plain gels can be used to thicken your paint, build up structural and textured marks, create thick lens-like glazes, and impasto effects. All of this is possible without the shrinkage and crazing (cracks) you can get when only using heavy body acrylic paint. They can create glazes from transparent and opaque colours but are not absorbent on the surface.
The Golden Extra Heavy Acrylic Gel was quite milky when it was first applied, so there was a big drying shift. It dried almost completely transparent, however, the thicker layers were more opaque so you could see where texture had been built up and marks had been made. It was easy to handle and create different effects.
The scratch marks were easy to produce and bit into the medium well without dragging it.
Painting over the gel was tricky as the acrylic paint got caught in the ridges and as I was using a semi-opaque Green Gold, this catching was far too obvious.
It dried to the touch in even the thickest areas in a day (the room was above 20 degrees).
It mixed easily with fluid acrylic, I chose a transparent Quinacridone Magenta, that created a gorgeous glaze, or rather lens, over an earlier painted mark.
It’s worth considering that the surface was not absorbent at all.
There was little shrinkage for acrylic and no cracking. This is because they contain more acrylic solids than most gels.
There are five consistencies of Golden plain acrylic gels the thickest being Extra Heavy Gel, then Heavy Gel, Regular Gel and Soft Gel, they also offer High Solid Gels that have a similar consistency to Heavy Gels but have even less shrinkage. Each gel is available in gloss, semi-gloss and matt finishes.
Molding pastes are opaque and are used to build up structures or provide textural effects, useful for topographical landscapes or creating 3-D textures in a work. It has a slightly porous texture due to the inclusion of marble or chalk particles and is fairly absorbent. Light Molding Paste is very lightweight making it useful for creating a lot of depth on large scale pieces. It holds peaks well but with slightly softer edges than created with the gels. They all mix easily with heavy body acrylic.
Extra Heavy Molding Paste created softened edges but still held peaks and marks really well. Due to the inclusion of some heavy gel in its composition, it is slightly smoother and less porous than other molding pastes. It mixed easily with heavy body acrylic and was fairly easy to paint on top of. It was touch dry, but slightly soft to the touch within an hour, and completely dry within 5 hours. It dries semi-opaque, allowing you to see through it slightly. The top was still quite absorbent.
It kept peaks exceedingly well and there was barely any levelling or deflation. Scratching into it was effective and didn’t create the ridges that scrapping into the Extra Heavy Gel created.
Molding pastes are usually very absorbent making them useful for creating texture on a surface or smoothing out a surface and then using the layer of paste as a ground.
Golden Light Molding Paste is 50% lighter than other Golden Molding pastes, this makes it a good choice for painters wanting to build a lot of texture without adding a lot of weight to a piece. It has a really foamy texture that is very distinctive and quite strange and feels very airy to the touch (a little light stiff mousse). It holds peaks really well and crisply, even very thin ones. You can see the distinctive peaks made with a palette knife in the right-hand swatch. It mixed with both fluid and heavy body acrylic easily. When it was unmixed it seemed semi-translucent, but even when mixed with a transparent acrylic colour, it seemed much more opaque.
While it was very porous, it was quite hard to paint over, as the colour pooled and sank in.
After a day, it was stiff but not dry to the touch. The shrinkage was noticeable but not extreme.
Molding paste is offered by Golden in the following ranges Molding Paste, Extra Heavy Molding Paste, Hard Molding (that dries to an opaque, very hard surface and is in-flexible so cannot can crack and flake off if not applied to a rigid surface), Light Molding Paste and Coarse Molding Paste (which is semi-transparent and dries to a stiff, textured surface).
Effects pastes are designed to create a distinctive surface texture through additives to the acrylic polymer.
Fibre paste can be used as a drawing ground or as a base for acrylic washes as it’s very absorbent. It provides a papery pulp texture that can be made smoother, if you skim it with a wet palette knife, or the texture can be emphasised by working a dry implement against the grain. It holds peaks and marks well and easy to mix with acrylic colour. It is very easy to control.
The texture, when wet, feels like wet paper pulp. Once dry, it feels exactly like a rough handmade or lightly processed, recycled paper pulp, I would not say it gives exactly a manufactured paper feel even once dry. It is an off white colour when dry, making for a nice ground.
It was easy to skim the top of the surface with a wet palette knife, to decrease the texture with both the pure paste and also the paste that had been mixed with acrylic. I was surprised at how smooth you could make the surface.
It was easy to scratch into and build structures as long as they were low, you could get flicks of paste to stay and dry stuck out, but not large peaks.
It was opaque but still slightly more transparent than I expected as you can see from the swatch on the left.
It was incredibly absorbent and felt really easy to wash over.
If you go against “the grain” after smoothing the paste, it produces a lot of texture and some nice “rucked up” effects.
By the end of the day, it was touch dry but easily dentable with a nail. After two days, it was very hard and you’d need to really scratch into it with something hard to produce a mark.
Crackle paste is an absorbent paste that cracks as it dries allowing anything underneath to show through the cracks. Colour washes over the top will run into the cracks. It is fairly hard to apply completely smooth and the size of cracks will vary massively with the thickness of paste applied.
I thought the finished effect was very striking, and was surprisingly absorbent, which could be a great advantage compared to other mediums.
The thickness with which you apply the paste, affects the size of the cracks that are produced. This needs to be at least a 1/8 inch thick to be effective but could be applied as thickly as 1 inch.
I was really pleased at the number of cracks produced after drying even on the thin layer. However, it’s worth considering that the size of the cracks is relative to the thickness applied. So if you apply it thickly, the cracks will be far larger.
I felt the paste layer, over a dried dark acrylic paint swatch, was really effective, as the dark under paint showed through clearly.
When I washed over the dried, cracked paste layer, it did absorb into the surface but also bled into the cracks that acted like waterways. However, this would be solved by going over with a thicker acrylic.
The thicker the paste was applied, the more absorbent it was. I noticed this most with the right-hand swatch, where the thicker end sucked up more fluid acrylic paint.
It was very difficult to make it smooth and show up tool marks very distinctly. It would be very useful if you wanted to create distinct levels within a piece.
The cracks could add an interesting element to depictions of cliff faces, mountains, rocks, or as an accent in abstract work.
Crackle paste is inflexible once dry so needs to be applied to a rigid surface to prevent it flaking off.
Gel with Aggregates
Clear Granular Gel contains uneven plastic crystal solids held in an acrylic binder. It extends paint and adds texture providing a transparent gem-like effect. It can build up structures and can be mixed with transparent acrylic colours. It has a translucent finish when completely dried. It is opaque when wet and looks like rice pudding which makes it slightly strange to use. It is difficult to paint over when dry and is hard to apply with any regularity.
Golden Clear Granular Gel, when wet, looks like rice pudding and feels very rough and gritty, as it’s full of little plastic shards. This makes it hard to handle, control and scratch into. Its opacity when wet, makes it hard to judge value, as it dries almost completely clear. Expect a massive colour shift if you’re combining it with acrylic colour.
The dried texture was interesting in how it reflected light, and the glaze effect, when it was painted over with a transparent colour, was very notable and pleasing.
The dried surface was fairly un-absorbent, meaning there was slight pooling when it was painted over. The colour was much more consistent when mixed through with the gel. While it dried transparent, it was surprisingly hard to see through after it had been mixed with colour and applied thickly.
You could achieve some mounds, if not peaks, and build up depth. The shrinkage wasn’t noticeable, due to the inclusion of plastic crystals, that were already solid. This is becasue the polymer acts mainly as a “glue”, rather than as the body of the gel.
After 8 hours it was still wet, but gradually was beginning to turn clear.
Golden Glass Bead Gel provides a shimmer on work similar to condensation on a window. It contains tiny glass beads in a binder that scatter reflected light. Popular with pouring painters, you can mix it with transparent colours to create boiled sweet effects.
The reflections are most effective when it is applied at a thickness of a single bead. Using a palette knife is the easiest to prevent the beads from clumping together and get a consistent layer. If you paint over the top, the paint will pool around the glass beads, without staying completely on the beads, and bleed out slightly between them.
It was fairly hard to achieve a consistent layer. I found the beads clump together and “pick” each other up.
It was quite absorbent as a layer to paint over, but the overpainted colour began to bleed out around the beads, making sharp edges hard to achieve.
It was very nice mixed with a transparent colour, producing a rich stained glass feel. It was fairly easy to mix, although obviously, you have clear beads in it and even when wet, looked quite translucent. Obviously, there was still quite a large colour shift. After 5 hours, the thin layer was touch dry, but the thick areas were still wet and all areas were a bit opaque still.
Doing a wash of colour over a thin layer of beads seems just as effective as mixing a transparent colour in.
It would be interesting to layer over already dried colour, and have it reflect the light on top.
Golden Pumice gels are used to introduce coarse sandpaper or concrete-like textures. These can be interesting to paint over, use mixed media on, or mix with paint to provide rough, coloured areas. It is very absorbent, but if you try to create high peaks, it crumbles slightly after drying. It is also fairly tricky to control.
Golden Coarse Pumice Gel was able to hold some peaks and had a grainy texture. It was quite difficult to control, and hard and messy to mix–especially on the palette. It was difficult to scratch into and removing areas cleanly was nearly impossible.
It was quite absorbent and had a lot of tooth when dry. It could be interesting to mix it with a colour and then paint over, letting the textured colour below show through. I found you can smooth it flat to a consistent sandy texture.
After six hours, it was still damp but you could see the binder’s milkiness clearing, so it was starting to dry. It was surprisingly more transparent than I expected when added to the surface thinly. The binder dried completely clear, but the surface was left slightly crumbly and the textural solids remained opaque.
Tar and Levelling Gel
Tar and levelling gel control how stringy the acrylic paint is, and prevent it from retaining brush marks.
Clear Tar Gel is used to create drips and strings of painting, like in Jackson Pollock’s work. It is easy to create strings when used neat but these dry completely clear and are prone to quite a lot of levelling and shrinkage. If mixed with acrylic (fluid is best) we recommend letting the mix settle in a sealed container overnight as otherwise, your strings will dry with air bubbles rising to the surface. You can apply the strings using sticks or a palette knife.
I found it quite hard to achieve decent strings after mixing the tar gel with fluid acrylic, and I found the working time was very short, before it started being too gloopy to make long strings. However, when used neat, it was very easy to control and create strings, loops and other effects. This may be because it needs to mixed and left to sit overnight. These drips that were unmixed, see the swatch on the right, were completely clear and levelled out quite a lot, as well as being un-absorbent on the surface.
The medium has a lot of potential, but requires some practice to understand. Apparently, using heat alongside will create interesting effects, so it would be interesting to experiment with this. Mixing water with the mediums did little to improve it in any way.
Within five hours of use, it was tacky to the touch and started to deflate. It dried to a very high gloss, and once completely dry, could still be dented with a fingernail.
Levelling Gel levels the surface of other acrylics it’s used with, smoothing any brush strokes or ridges made during application. It has a resinous, stringy consistency.
Glazing Liquid lets you create oil-paint-like glazes and blend acrylic colour for subtle colour transitions. This allows you to work in a similar way to oil paints, without the difficult cleanup. It gives acrylics a longer working time and a stained glass effect. It will make acrylics very fluid and prone to bleeding on absorbent surfaces.
The glazing liquid was very easy to use and handle. It kept marks and pooled slightly, but created flat gorgeous glazes. Blending the acrylic colours into one another was super easy and the colour shift was bearable. It dried completely clear. It did feel quite thin and bled out. This may make creating sharp edges difficult.
After an hour, the thinner area had dried, but it was still tacky in the thicker areas. Interestingly it’s described as slow drying which felt untrue.
Additives by Golden include, a retarder that increases the drying time of acrylic, Open Thinner that thins the consistency of Golden Open colours without changing the drying time, and a Wetting Agent which reduces water tension and increases the flow of acrylic paint.
Golden GAC mediums are additives that change hardness, flexibility, fluidity. All of them are more fluid than any other Golden acrylic mediums, including Golden Fluid. They contain a minimum amount of thickeners, levelers, defoamers and surfactants to ensure good film formation. There are seven GAC mediums, some of these can also be used as binders. Each GAC is a unique polymer with distinctive characteristics. They have a minimum amount of thickeners, levelers, defoamers and surfactants to ensure good film formation.
This is the most commonly used polymer in paint and is the most flexible with a moderate amount of tack and gloss. It can be used for diluting and extending colours, especially if film flexibility and integrity are important. Ideal for artists creating their own acrylics.
The hardest and least flexible of all Golden products, it increases film hardness and needs to be used in pure form on rigid surfaces. It also needs to dry at a minimum of 21 degrees. It improves adhesion to non-porous surfaces. Dries to a high gloss with an excellent transparency. Useful for hard edge techniques as it has less pull than other acrylic compositions.
Dries to a hard, stiff film, making it useful for priming canvases if stiffness is required. It can be used as a rabbit skin glue alternative.
Self levelling with some flexibility. Best used as for a spray-applied isolation coat. Two parts of GAC 500 mixed with one part High Flow Medium produces a good spraying, fast-drying isolation coat. Useful to hard-edge painters to seal masking tape for cleaner edges. Apply over masking tape. Let dry before applying additional paint layer.
Increases film clarity and dries to a clear high gloss with a moderate hardness. Offers little shrinkage over the course of drying.
Reduces crazing and is useful for pouring. Dries with good film flexibility but a slight haze on the surface. Can be used to make an acrylic adhere better to chalky surfaces.
Designed to make acrylic paints more suitable for use on clothing. Offers a soft pliable feel and is machine washable once heat set.
Golden Matte Medium is often used as a good clear primer in studios. It is thin enough to penetrate porous substrates, but the matting solids mean it provides enough tooth for subsequent layers. The paint adheres much better to a matt surface. It also extends colour and increases film integrity.
Golden Fluid Matte Medium also increases film flexibility, extends colours and increases the fluidity of paint. It can also be used as a primer on canvas.
Both matting mediums, when several layers are used as a primer on a dark porous substrate, can dry with a frosted effect, as the matting solids are left on the surface, while the acrylic primer permeates the surface.