Paint Brushes - Synthetic vs. Natural Bristles

[Brent Fordham]

This question has to do with synthetic vs. natural bristle brushes when used with acrylic paints. At the artist supply shop last weekend, I asked the clerk what the difference was between watercolor/acrylic and oil brushes. Her answer was interesting: she said that natural bristle brushes have pores that soak up water and tend to dry out faster when using acrylics and water colors. This of course, isn't a problem with oils. So, generally, oil brushes are natural bristle and acrylic are synthetic?

One problem that I've had when detail painting with acrylic is that the brush dries out too quickly. I have been using W & N Series 7 (sharpest points I've ever found). Should I be trying to find a synthetic bristle alternative?

 

[Szaven]

I'm using the same brushes like you and detail painting is really pain in the ass.

For the eyes I tried pigmentliner from edding, that's a nice alternativ.

Looking forward to see other alternatives.

 

[Einion]

Hi Brent, there's a rule of thumb with acrylic that you should never load them into a dry brush If the bristles are damp and the problem still occurs (and it does) then I think that explanation is bogus. Although capillary action may play some part evaporation is always going to be the major factor.

With the diluted paints generally used in the hobby there's a lot of water anyway, even straight from the container Vallejo, Andrea, P3, GW, etc. have a significant water percentage in 'em, otherwise they wouldn't be fluid. Acrylic/vinyl paints dry by evaporation and this is fast. That's most of it; the drier the environment the worse this is, so if you live in an area with low humidity you'll tend to have much more trouble in this are than someone who lives somewhere with high humidity.

The general ways around this are adding a retarder of some kind, reloading the brush regularly (good habit to rinse thoroughly and often, helps brushes stay cleaner too) or painting faster. Or some combination of these.

So, generally, oil brushes are natural bristle and acrylic are synthetic?

Not really. Lots of brushes are multi-use anyway, regardless of how they're marketed to artists. Some oil painters - painters, working on canvas etc. - use all synthetics instead of hog bristle and some acrylic painters use hog bristle instead of synthetics, sable/Kolinsky rounds tend to be used by all types, and so on. Basically people use what they like a lot of the time, even if it's no 'supposed' to be for their medium.

One problem that I've had when detail painting with acrylic is that the brush dries out too quickly. I have been using W & N Series 7 (sharpest points I've ever found). Should I be trying to find a synthetic bristle alternative?

There is more than one type of Series 7 brush, you may be using the miniature version. Although of course a 0000 is small in any range the miniature type has much shorter bristles and less paint in the brush head = faster drying. This is one of the main reasons I recommend using the largest brush possible generally.

Einion

 

[magister militum]

If you are concerned about fast drying acrylics, I recommend using a retarder. After switching to Series 7's, I'll never go back to cheaper synthetics. My 7's have lasted me over 2 years now and the points are still going strong.

 

[Brent Fordham]

Thanks for the advice Einion and Magister,

Einoin, you make an excellent point regarding not loading acrylics onto dry brush. If a natural bristle brush is already saturated, it can't soak up any more water, so after a point, you're right, it can't be responsible for the brush drying out.

Being an oil user, some of these acrylic issues are new to me. After reading a few good "how to" books, the importance of using a clean water supply to constantly dip and clean the brush is becoming more apparent. I do use retarders regularly, but they are not sufficient by themselves. I will have to try some of your other tips as well.

I do live in a very dry climate, especially in the winter, but had never before considered this as being part of the problem. I have a small humidifier and will use it the next time I paint to see if it makes a difference.

I'm glad to hear that I don't need to be too concerned about synthetic vs. natural bristle brushes. I have always selected a brush based on shape and texture.

Thanks again for the help.

 

[Einion]

Another thing you might like to try in terms of brush rinsing is a double-bath system, with one large jar and a second one (usually smaller) for final rinsing. This stays clean for ages, so you can use it for dilution without any risk of polluting a subtle colour if you thin with tapwater.

You might like to also try a little dishwashing liquid in at least the first jar, this helps in the cleaning obviously but it also acts like a mild flow improver which is usually beneficial.

Since you're new to these kinds of paints there many good threads on CoolMiniOrNot that you'll find helpful. Some samples:
Ten Commandments of painting....
Cleaning brushes
W&N#7 brushes....best brush cleaner???

You can look for more on layering, glazing and nearly anything else you might think of.

Einion

 

[Jamie Stokes]

Thanks for the links Einion,
interesting browsing

Cheers

 

[Brent Fordham]

^ Ditto. More good information - much appreciated!

 

[Jehan17]

I have had the same problems when I started using acrylics with my W&N series 7. For me the problem was not the paint but the brush. I had noticed that the mini painters in my region all used Raphael series 8404 brushes; they are Sable/Kolinsky based but have larger reservoirs to hold more paint while the tips are as fine as the Series 7. They where a revelation for me, all of a sudden I could paint with acrylics, no more messing with medium and retarder.

Here's a link:

http://www.dickblick.com/products/raphael-kolinsky-red-sable-fine-pointed-round-series-8404/

You got to use the right tools for the job is what I found. Give them a shot.