Golden SoFlat Acrylic for Hard Edge Abstract Painting

23rd November 2023 by Julie Caves 8

Golden SoFlat Matt Acrylic is the most opaque, self-levelling, and matt paint of all the ranges that Golden Acrylics make. The opacity means it is very well suited to flat, graphic style work, so I thought I’d try it for the first time by painting some hard edge paintings and doing some colour mixing test charts on paper. The velvety matt surface was lush and the quick drying time let me get on with all the layering stages of this type of painting. I had a lot of questions including: Why not just add matt medium to regular acrylic paints? And does it look different to adding a final matt varnish to regular acrylic paint? And is it a type of acrylic gouache? After painting with it I can answer those questions and describe the many characteristics of this interesting paint.

What is Golden SoFlat Paint?

It took Golden some time to make an artist-grade acrylic paint with all three of the characteristics of this paint – opaque, self-levelling, and matt – because they contradict one another. Opacifying agents and matting agents add solids and thicken the body of a paint which is the opposite of what you need when you want a thinner-body paint that levels out smoothly with no brushmarks. They have used a special binder and flow additives and for a few colours have added some white pigment (which is always listed with the other pigments on the label). Some pigments could only be made semi-opaque or the colour would have been altered too much, so they require two coats for full coverage, but all the colours are velvety matt and level out smoothly.

They also use artist-grade pigments in the same pigment load as their other artist-grade paints. And you don’t need to add any water to get them to the right consistency to flow well.

A 59 ml pot of Golden SoFlat acrylic in Pale Yellow (A single pigment colour PY53.)

They warn that because the binder is thin enough to self-level, the paint may need a stir if the pigment settles to the bottom a bit or that there may be a layer of clear liquid at the top of the jar that will need to be stirred back in. I didn’t find any separation, but that might have been because they were well agitated in the post! If you do stir or shake the pots, you don’t need to worry about incorporating bubbles, because a side effect of the self-levelling part of the formulation is that bubbles don’t stay, which can be a problem in other acrylic paints, leaving pinholes in the dried paint film.

Matt Sheen

Pigment affects the sheen of paint. Golden don’t adjust for that variation in sheen in the rest of their ranges, they let the pigment determine the amount of gloss or matt, so each colour is slightly different. But with their SoFlat paint, all the colours are completely matt. It’s a deep, velvety matt-ness. It’s great when photographing your work, because there is no glare or reflection from the surface of the painting.

Body

Golden SoFlat paints are creamy, a bit more fluid than Golden Fluid acrylics, with a slight stringiness. They are thixotropic, meaning a colour may be thicker in the pot until you stir it, then it flows more, and it becomes a bit more fluid as you brush it out.

Pouring from a 59 ml pot of Golden SoFlat acrylic. This is Ultramarine Blue (PB29, PW6).

Self-levelling

If you use a soft flat synthetic brush, as wide as will work for your design, and you apply the paint with the brush held at a low angle, you’ll have few brushmark ridges. They will then smooth out as the paint settles and any small amount of brushstrokes left after drying are hard to see because the surface is so matt, there is no reflection off any slight ridge. It relaxes in a way that is unique to this paint, melting into the surface without spreading. I used Jackson’s Icon brushes and they were great with this paint.

The surface has a very flat even appearance.

Flexibility

SoFlat can be used on rigid surfaces like wooden panels or flexible surfaces like stretched canvas or paper. In spite of being full of opaque solids, the paint has sufficient flexibility to allow for the expansion and contraction of canvas due to humidity. I applied some fairly thick layers, holding the brush at a very low angle to allow lots of paint to flow from the brush, and these areas didn’t crack even when dried quickly with a fan.

Opacity

SoFlat has good coverage because of the high pigment load as well as the opacifiers. You get good coverage in one coat except for a few of the colours that are semi-opaque because they decided that the colour looked best in that formulation. If an area was streaky and I didn’t want that, I found that waiting 5 minutes for it to dry in front of a fan and then painting a second coat in the opposite direction, worked well for complete flat coverage. There is a versatility to it being semi-opaque in thin layers and opaque in two coats or a thick coat. They suggest adding a touch of water when applying a second coat if you are layering, because the paint is so absorbent, I often use wet brushes and that was enough.

I was able to easily and evenly cover the first colour with a new colour. The orange is shiny because it is wet. It will dry fully matt.

Hard Edge Painting Technique

The fast drying time of acrylic paint makes it perfect for hard edge painting, a type of abstraction that uses masking tape for sharply defined shapes. Using a matt acrylic like the SoFlat really lets the colours glow, and because there isn’t any glare, the shapes look more dense.

Peeling off the 1 inch wide tape from around the shape and the 1/4 inch tape from the inside of the shape. I added a lot of the Super Matt Medium to the SoFlat white to make it more transparent.

The key to getting sharp edges with masking tape is to seal the edge of the masking tape to prevent the paint seeping under to leave cauliflower leaks. These are the steps: apply the low tack tape, with your fingertip rub down the edge you will be painting over, apply a clear acrylic medium along the edge and rub down again while wet, let dry, apply paint, remove the tape. If you are happy with one coat of paint then remove the tape right away while the paint is wet so you can use the edge of a damp brush to wipe away any little leaks that got through, while everything is still wet. If you want to apply a second coat of paint, then dry the first coat and apply the second and you can remove the tape then or after it’s dry and you are sure you’re happy with the paint.

Pulling of the tape to reveal nice sharp edges, even on the textured surface of canvas, because the edges were sealed with acrylic medium.

The acrylic medium I usually use for sealing tape is Golden GAC 500. You can use clear gel or most other clear mediums. The way it works is that a little of the medium seeps under the tape then forms a seal at the edge of the tape. The leaks aren’t visible even if they are on top of another colour, because they are clear. This changes when you are working with matt paint, because the clear leaks are very shiny on the matt surface and no longer an invisible way to do the technique. So you need to use a matt medium. But matt mediums are really sort of satin and the leaks from matt medium were still very visible. The only medium I found that worked to seal the tape when painting with SoFlat was Golden Super Matt Medium (formerly called Super Loaded Matt Medium). It’s a lovely product. For this technique a little goes a long way. After trying a few things I found that using my finger meant I was able to use just a small amount of medium. I dipped my finger in the pot and applied it along the edge of the tape, then ran my finger over it a few times and then feathered any excess medium towards the centre of the shape, so no ridge was left to create texture under the paint. It formed a great seal every time and I only needed to do it one time to seal the tape.

My go-to matt medium – Jackson’s Fluid Matt Medium – did not work for this; like all matt mediums it’s too glossy compared to the SoFlat paints, so the little cauliflower leaks showed. I don’t know why but it also tore the paint so didn’t leave a sharp edge.

Using the Super Matt medium for the tape sealer made it completely invisible.

I use a fan to dry each layer of sealant and paint. I avoid heat like a blow dryer because this usually causes cracking and you have to stay there and hold it. Using a fan reduces the drying time of each step to just a minute or two, but you can save even more time if you work on two paintings at one time, moving the wet one to your drying area with the fan and bringing the dry one to your painting area to work on it, swapping out back-and-forth.

You can read more about this method of painting in Sealing Your Masking Tape For Better Hard Edges In Acrylic Painting.

Layered Shapes Pink and Green Painting

For all the other paintings I did shapes next to each other. With this painting I wanted to check a few things including how it worked when layering the shapes. I glazed with Golden Super Matt Medium added to SoFlat white for transparency. It worked great and it was odd to see glazing that wasn’t super shiny, it was sort of confusing until I got used to the idea! I wanted to see if a small amount of gloss magenta would affect the sheen of the white SoFlat. It didn’t, you can add up to 20% regular acrylic and it will still be matt. You can read more about that in the results section below. Then I wanted to see if removing the tape pulled off the gesso of the gesso panel – it did not. And if the tape pulled off the paint of the layer below. It didn’t, even if the paint had only been dry for a minute.

This painting is on a Jackson’s Cradled Gesso Panel, which are lovely surfaces, solid and ready to use as soon as you unwrap them.

The light green is a mixture of Phthalo Blue, Pale Yellow and White. Notice how it is fully opaque. The white shape below has lots of super matt medium mixed in to make it transparent.

The white shape on the left has been used neat and the white shape on the right has been made more transparent by adding Super Matt Medium.

The finished green and pink layered shapes painting.

Characteristics I Investigated

Is Soflat the Same as Adding Matt Medium or Super Matt Medium to Regular Acrylic Paint?

To answer this question, I made a painting with 16 shapes using Golden Fluid Phthalo Blue and SoFlat Phthalo Blue – used neat in different thickness and layers and then mixed with different amounts of gloss medium, matt medium, and super matt medium.

The Fluid paint alone was glossy and transparent. Adding Fluid Matt Medium, Matt Medium or Super Matt Medium made it more transparent. To get it to go from glossy to a satin/matt meant there had to be three times as much medium as paint, and it got very transparent and light coloured, essentially a glaze mixture. With the Fluid Matt and the Matt Medium, at 75% medium and 25% paint, the mixture was still only satin, not fully matt. Using the same amount of Super Matt Medium, it became fully matt, though still transparent and light coloured because the pigment was so diluted. So you can’t add a medium that makes the paint matt and opaque.

With transparent colours like Phthalo Blue you can control the light colour either by adding white or making it thinner, if the surface behind is white, like you would with watercolour. With the SoFlat, you can only make it lighter by adding white. In SoFlat the Phthalo Blue is semi-opaque, so for full coverage you need either a thick coat or two regular coats.

Fluid Matt medium mixed with Fluid paint in 3:1, 2:1, and 1:1 ratios. The more medium that was added to the gloss paint, the more satin the mixture became, while becoming more transparent.

Super Matt medium mixed with Fluid paint in 3:1 at the bottom is the most matt and the most transparent, 2:1 in the middle is still matt but with more paint, and 1:1 at the top is satin. The more medium that was added to the gloss paint, the more matt the mixture became, while becoming more transparent.

SoFlat neat, 1 thick coat.

SoFlat Phthalo Blue neat, 2 coats.

SoFlat Phthalo Blue neat, 1 coat.

Neat Fluid Phthalo Blue is transparent and glossy.

3 parts SoFlat Phthalo Blue to 1 part fluid Titanium White. Lightens the colour while remaining very matt an opaque.

Can You Apply Matt Varnish to Regular Acrylic Paint and Get the Same Result as Using Soflat Paint?

I tried both the Golden Spray MSA Archival varnish and the Golden Polymer varnish on Fluid acrylic to see if they’d make it look as matt as SoFlat. Golden Fluid Phthalo Blue naturally dries glossy, unless thinned with water when it dries to a satin finish. I applied a coat of polymer matt varnish on top and it made it completely matt similar to SoFlat but the SoFlat Phthalo Blue had a more even, dense coverage of colour than the Fluid with matt varnish on top and was more velvety matt, much more lush.

One coat of Polymer Varnish matt on one coat of neat Golden Fluid. The result does not look anything like a coat of SoFlat paint. It is not opaque, streak-free, or brushmark-free. It is not velvety or rich.

Blending

As you can see in the only non-solid section of this painting, blending works just fine with the SoFlat paints.

Diluting

Unlike acrylic gouache it’s already a more flowing viscosity without the need for any water. Because you can use it unthinned it will have a higher pigment load and be more opaque. Using the widest flat brush possible will mean fewer ridges but even brush marks from a small brush will level out; they will lessen but not completely disappear.

Colour Range

Golden introduced SoFlat in 2021 and expanded the range to 60 colours by adding 20 new colours that we just received at Jackson’s last month. I did my review before we had received the new colours so the colours that I chose for my mixing set of six weren’t perfect for blending. I would have liked a magenta to mix good violets, but settled for pyrrole red which isn’t as cool of a red, so my violets are a bit brown. I’m pleased to say that the new colours include a magenta, as well as crimson, cobalt blue, olive green, 14 pastel shades and two greys. The range also has six fluorescent colours (which, like all other fluorescents, are not lightfast). Some colours in SoFlat are not available in the other Golden lines.

Using a warm and cool of yellow, red and blue I mixed the secondary colours well except for the purples, because I did this before they introduced the magenta, so I used the coolest red in the range at that time, Pyrrole Red.

From top to bottom:
Permanent Yellow Deep mixed with Ultramarine Blue.
Permanent Yellow Deep mixed with Phthalo Blue.
Pale Yellow mixed with Ultramarine Blue.
Pale Yellow mixed with Phthalo Blue.

Washes

Interestingly, when Golden Fluid paint is used with lots of water in a washy way, it’s just as matt as washy SoFlat or the two acrylic gouaches that I tested when used in a washy way. They all looked like watercolours. But because acrylic is waterproof, it’s not as fragile as watercolour.

SoFlat with various amounts of water added for washes.

Pigment Load

After a number of tests and paintings I can say the SoFlat has the same artist-grade pigment load and quality of pigment as the Golden Fluid paints have.

SoFlat on the left and Golden Fluid on the right. Both Phthalo Blue green shade.

Mixing With Other Acrylics

To get colours that are missing from the range you can mix SoFlat with other types of acrylic; they’re intermixable with all other acrylics. You can add up to 20% regular glossy acrylic paint and it will still be full matt, but more than that and it becomes satin. So if you need a colour to mix with, it will work if you can keep the regular acrylic amount small. I wanted a pink and used 1% fluid magenta in the SoFlat titanium white and it didn’t change the matt at all.

Pinks and purples could be mixed by adding a small amount of magenta in regular acrylic, and the SoFlat still stayed matt. But you won’t need to do this now that SoFlat have added magenta to the palette. But you may wish to mix with another colour that you don’t have in SoFlat and it works fine.

Drying

SoFlat ries quickly, even more quickly with a fan. I use a fan without heat to dry each layer and each sealing of the tape, when I’m painting hard edge shapes. Most colours are semi-transparent when applied thinly but opaque in two or three thin coats. The fast drying time of acrylic means that you can apply the next coat in 5 or 10 minutes or if using a fan, 1 or 2 minutes. I found that with SoFlat I can lay down a thick opaque coat in one go and it doesn’t crack. But even though it dries quickly on the canvas, I found that it didn’t dry super quickly in my brushes which was great.

Wet to Dry Colour Shift

I was having trouble deciding if there was much of a colour shift, sometimes it seemed like there was a moderate shift and other times not, it may have been my lighting and the angle I was looking. So I painted out four colours in two versions each – one neat and one mixed with white – and let it dry. I then painted the same colours next to them and took a photo while it was wet. It dries so quickly that I had to work fast. But this chart showed almost no colour shift. The shift may be more apparent in darker colours – some become a bit darker and a bit duller.

I used four colours straight from the pot and mixed with white.

I then painted these 8 colours onto paper and let them dry. I then painted them again and compared the colours next to each other and there was almost no change from wet to dry.

A mixed green, wet.

The same colour dry.

Surfaces

I painted SoFlat on two types of paper, primed wood, primed canvas panel and stretched canvas. Adhesion was good on all surfaces though my two favourites were the primed wooden panel because the smooth surface helped the velvety flatness and the acrylic paper because it is thick and the paint sinks in for a lovely flat surface. If you like flat paint with very little visible brush strokes, that sits in the paper fibres like a lush screen print, then you’ll like the SoFlat on Jackson’s acrylic paper. I don’t recommend it on Jackson’s oil paper because that paper can’t get wetted and when I brushed lightly with some water to remove a paint drip, it made a hole. It’s a soft paper and was torn by even low tack tape, so was not useful for hard edge painting, either.

Jackson’s Cradled Gesso Panel

Jackson’s Acrylic Painting Paper

Format

I compared SoFlat with Golden Fluid and two acrylic gouaches and SoFlat is the only one that comes in a jar, the other three are in tubes or a squeeze bottle. This means that SoFlat has to be dispensed with a palette knife if you are mixing it on a palette but if you are using it neat, you can dip your brush directly into the jar. SoFlat comes in three sizes of jars: 59 ml, 118 ml and 473 ml. They also have two sets of six colours.

Is It Like Acrylic Gouache?

Golden say that SoFlat can be used as you would use an acrylic gouache but the fact that it is ready to brush out without needing to add any water makes it different, it makes it more opaque because it can be used undiluted.

Large Areas of Streak-free Colour

These paints are great for colour field painting with large areas of flat colour and for the flat shapes in hard edged painting. To get a really dense streak-free solid layer, I found that most of the time I liked to apply a second coat in the opposite direction. Since the coverage is so good, I could also alter the colour of the second coat a little if I wanted to change it and it would still give the full dense coverage of two coats, even if the coats weren’t the same.

Flat, dense, streak-free colour that can cover previous colours easily.

Glazing

I glazed white over the red-orange in this painting by painting a thin coat of white mixed with super matt medium.

Adding Acrylic Mediums

Pour Painting: I didn’t do any pour painting but they say the SoFlat can be used for acrylic pour painting at a ratio of 10 parts pouring medium matt to one part SoFlat. And it won’t develop bubbles, so perhaps it will help with the pouring medium bubbles.
Transparency: If you want to increase transparency without increasing gloss, you can use Golden Super Matt Medium. It will make it less opaque because you’ve diluted the pigment.
Body: If you want to add body for texture, you can thicken it with Extra Heavy Gel Matt or Light Moulding Paste. This is great for painting with a stencil where you add thick colour in the shapes and smooth with a palette knife – it should give you a raised, matt design similar to flocked wallpaper.

Fragility and Durability Questions

The only problem I found was that it is a more easily damaged surface than regular acrylic which is durable and wipeable. There were some abraded areas that happened while I was painting, areas that got rubbed during the painting process. But the surface is much more durable after it has cured for one or two days. And it’s such a lovely surface that I think it is worth taking care for the first couple of days.

Being easily marred in the first 24 hours doesn’t include being damaged by low-tack tape so it’s great for hard edge painting. Tape doesn’t lift any paint that it was stuck on to, even if it had only been drying for 5 minutes.

Rubbing the surface, even when it is dry, can mar the surface until it has cured for a day or two.

It’s very hard to photograph but the surface showed scuffmarks from light finger rubbing, like when the nap of a velvet gets rubbed the wrong way, And a shiny patch from a light burnishing.

Another view of the same spot.

Tape doesn’t lift any paint that it was stuck on to, even if it had only been drying for 5 minutes.

With SoFlat I found I rarely succeeded at touching up a flaw. I found that when I tried to touch up a spot, the sheen was slightly different because the brushstroke was in a different direction or something, and when it dried it was visible, so I found it was better to just paint over the whole shape again like the first time. Tape it off and repaint the whole section because there is just enough wet to dry colour shift to not be able to match the colour. Or even if you still have some of your original paint mix left, there may be an angle of texture that is detectable.

This shows a patch that was brushed on later, straight from the pot just as the first. But after drying, it shows up slightly different. In this case I think it was a thicker layer, which gives it a slightly different sheen. I ended up just painting another complete layer over this shape to get a perfect surface.

The fragility seems to be affected by adding water instead of a medium so it’s a stronger surface if it’s used without water. And a thick coat is stronger than a thin one. I thought that perhaps the fragile surface could be protected by using a varnish on top, but the matt varnish has the same surface that shows finger rubs or nail burnishing.

While photographing one of the paintings it fell forward off of the shelf, onto the top edge of a gesso panel sitting below. I thought the paint had been badly scratched and was ready to repaint the three affected shapes. But after testing with my fingernail I found that the marring was gesso deposited onto the painting, not a scratching off of the paint. I used a scrubber brush and lots of water and most of what looked like a scratch came off. I ended up only repainting one shape because along with the gesso a bit of the paint came off.

I found that sometimes watermarks showed, so if water got speckled on the dried paint, or it dried unevenly, a ring would form that couldn’t be brushed off or rubbed out. But I found that waiting a day for the paint to cure and then wetting the whole surface and wiping it dry gently with a cloth over the whole surface removed the stain. Maybe it’s like brushing up the nap of suede or velvet.

Does Applying a Matt Varnish Onto the SoFlat for Protection, Change the Appearance?

I have always recommended varnishing all acrylic paintings for durability. The surface of acrylic is soft, porous and slightly tacky and adding a hard varnish surface on top stops dust getting embedded in the surface over the years and lets the painting be wiped clean. And if you’ve used a lot of mediums and gels it’s worse, then your painting will be very tacky even when cured, but a varnish solves that problem, so your paintings don’t stick together and pull paint off of each other.

So I thought that maybe applying a matt varnish would solve the durability issue with these paints. But in my tests, the blue SoFlat with a matt polymer varnish was darker, less blue, and less rich than the unvarnished paint. It lost all its velvety lushness. I had an email exchange with Golden Paints and they confirmed that all matt products are more prone to marring and getting shiny spots burnished on. And that using a matt topcoat over the SoFlat paints to reduce marring, will cause the colours to become desaturated and dull.

One layer of Golden Polymer varnish on a shape painted with two layers of neat Phthalo Blue SoFlat. The varnish made it less blue, more black, darker, and duller. It took away the richness and velvetyness.

I usually use a water-based acrylic varnish because I have more control of thickness, evenness and sheen with a brush than with a spray, plus the Golden archival MSA spray varnish leaves a permanent strong odour on the artwork and you can’t use it indoors and it’s not really necessary unless you are using it on an outdoor mural. But I did also test the spray varnish and it added some matt sheen with one light coat but it was speckled. (When asked, Golden said that might be because SoFlat is an absorbent surface, so would need an isolation coat to get an even spray varnish appearance.) When I added a second coat to get a more even coat it became shiny, even after three minutes of shaking the can to mix in the matting agent, and it got more shiny the more coats I sprayed on as I was still trying to get even coverage. The spotting from the spray showed up much more on the SoFlat than on the Fluid paint. Polymer varnish applied with a brush worked much better for me.

The matt varnish on both the SoFlat and the Fluid paint was able to be burnished to a glossier patch with a light rubbing with the back of a fingernail to leave a shiny patch, so either way the matt surface can be marred by removing the matt-ness with abrasion, whether it’s matt varnish or matt paint. It seems to be more obvious on dark colours.

So the SoFlat will need to be left unvarnished and you’ll just need to take a bit of care when handling the paintings.

Overall, I found the SoFlat acrylics to be unique paints, that were lovely to paint with and gave a gorgeous result. If you take a bit of care with the surface, these are beautiful paints.