Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

You can send an email to [email protected] if you have questions about how to use this forum.

Using Mark Carders medium recipe - Toxicity?


I do not live in the US, so cannot buy Geneva paint. I have just bought Schmincke Norma professional oil paint instead.

I will be following Marks medium recipe to give all the colours a similar consistency/flow.

The question, however, is - how toxic will the paints be when mixed with the medium. Gamsol odourless mineral spirit is only product that seems toxic.

Given the paint, when mixed, will be in mason jars, and only small portions on my palette(s) I feel this should be fairly minimal in toxicity. But I would appreciate feedback on this!

I will be using a small room to paint in with open windows and a continuous fan circulating the air.

I will be using my own brush dip (Marks recipe) and will clean brushes (gamsol) in a different area from where I paint, well ventilated.

Cheers in advances for the community support :)



  • geoffrey_38

    Geneva is available in Europe and Australia.

    Using the formula medium for about ten years with OMS. The only noticeable odour is clove, I ensure good flow through ventilation as OMS emits masked toxic vapor.
    By not drinking or washing hands with gamsol, the hazard is inhalation

    Experiment with a citrus solvent as an ingredient in the formula.

    The solvent will ruin your brushes. Use an immersion oil bath between painting sessions.


  • Thanks. I live in New Zealand. We have high taxes for imported products so after much maths it is a lot cheaper to make my own free flowing oil paint - as per Marks instructions on his website. What is OMS?
  • Sorry, just realised, Odourless Mineral Spirits.
  • I'd skip the OMS and use walnut oil or another thin bodied oil and try that. You might like it, you might not, but if you do it saves you having solvent fumes to deal with.
  • edited February 23
    Thanks, Richard_P.
    But I am trying to do things properly or at least follow Marks advice until I find my own mediums. Give it 30 or 50 paintings away, lol.
    I am following Marks medium recipe, which has odourless mineral spirits:

    Important to say that Marks paint has no toxins, but his medium mix does for those unable to buy his paints. Which is why I am asking how toxic his medium recipe is.
  • I do not use any solvents at all.  I work in a small room with little ventilation.  I use walnut oil with a small amount of clove oil.  I dip brushes in safflower oil with 2% clove oil when they are not being used.
  • edited February 23
    I love using walnut oil as a medium, I find it really light and it apparently does not yellow like other oils.

    Having read on the forum recently that a lot of commercial cleaners actually ruin brushes I am starting to clean them in walnut oil too.
  • Your plan and ventilation is sound but I agree that you should avoid gamsol or OMS for cleaning brushes. Use brush dip the way Mark talks about in his "painting with dirty brushes" video. Once the mediums are mixed with the paint there is no great danger of toxicity unless the ventilation shuts down. I do the mixing outdoors anyway mostly because the coves smell.
  • Thanks for the advice.

    Seems people don't like gamsol for cleaning. I was not meaning I would be cleaning the brushes regularly (like Bob Ross use to do, lol), as I will be using brush dip and Mark's method for how to paint in dirty colours. 

    I was meaning storing brushes when finished or starting a new painting. I see there are alternatives to Gamsol, like oils and soap. Well soap is a must to get them really clean for storage. 

    Thanks again.

  • You also have to take into account how toxic the paints you are using are.  Some paints have toxic components in them either the pigments which would normally require that you inhale dusts, or ingest the pigments; But the additives can also be toxic.  All of this should be easily ascertained from the literature or MSDS sheets.  I get suspicious if the paints dry reasonably quickly.
  • Thanks TamDeal. I'm using, what I believe to be, the most readily available and high quality paints in New Zealand. Schmincke Norma Professional oil paint. Winsor and Newton are rare in New Zealand. I would much prefer to use Geneva but all in good time. Like cheese and wine, good things take time you know. 
  • There are very cheap paints that are non toxic, the problem can be that to get the primaries, you end up with recommendations that include cadmiums.  Apparently some of these are not toxic.  It is the driers and such, that they put in the paints that can also  be a problem.  I also see prep videos in particular where people are sanding stuff.

    The one thing that I notice in the modern craft environment is that there are people who while amateurs often enjoy their crafts with exposures that take them into professional risk levels.  For instance a friend of mine just wound up his build of a 46 foot catamaran.  That is a huge project, like 10 years in his case. An acquaintance in Australia built a 38 foot catamaran in a "garage" that he could barely slide past the boat in.  So you get huge time commitments in insufficient spaces, with chemical exposures that can be significant. 

    I was watching this professional portrait video, and the guy was working in a studio the size of a country church.  Compare the exposures there with a low ceiling, basement bathroom studio.  :)

    Of course, a little ventilation and common sense, and all is well.
  • I am careful because in Canada we are shut-ins about half the year, so good ventilation is whatever comes in the door with the mail.  :)
  • CJDCJD -
    edited February 27
    Driers are typically only used if the binder is safflower oil. Shouldn't be using paint with safflower oil in it to begin with.

    In many cases additives actually slow drying. For example rublev lead white 1 is the fastest drying lead white bc it's the only one without additives besides linseed oil and pigment. 

    I like the walnut and clove idea. Ditch the clove once you're good at mixing colours.
Sign In or Register to comment.