I was surprised to see the assertion in Judy D. Treman’s book “Building Brilliant Watercolors” (Northlight books, 1998) that tube watercolor paints are formulated differently from dry pans and are not meant to be allowed to dry on the palette and “activated” by rewetting them. She has communicated with a paint manufacturer (whom she does not identify but is probably Winsor and Newton) who supports this assertion saying that they formulate the paint differently for tubes versus pans and has published on this issue.
Here is a Dick Blick video supporting Treman.
http://www.youtube.com/watch?v=6eD6L…layer_embedded
There is a question of whether a different formulation for pan versus tubes is universal among watercolor manufacturers. You may not know it but the German paint company AB Wilhelm Becker has acquired Winsor & Newton, Reeves, Conte, Lefran & Bourgeois, Liquitex, Colart, and Snazarro (face paint). Friends of mine insist that paint has changed since this happened.
Virgil Carter, as he reported on WetCanvas, has asked many watercolor manufacturers if there was a difference in the formulation of the paint in their tubes and their pans. Only Winsor Newton reported that there was a difference. They put more anti-mold preservative in the pan paint because it will be re-wetted many times. They do not do this with their tubes because they do not expect them to be dried and reconstituted. They do not reveal more about their formulas for paint which seem to be individualized for each pigment, but they might put more humectant (water absorbing material like honey) in the tube paints.
Winsor Newton feels that reusing their tube paints once they have dried will
1. encourage mold (from the added moisture)
This makes little sense to me. Constantly moist, warm paint that is kept in the dark is in the best conditions for mold to grow. It seems to me that wetting and rewetting the old sort of watercolor paint for a short period of time and then letting in dry completely will add only a little risk of mold. Wetting and re-wetting is not the same being kept wet all the time. However, some tube paints have been formulated with enough water-holding additives like honey that they actually never dry past a sort of gummy stage. This might keep them wetter for longer periods of time thus increasing the risk of mold spores, which are everywhere in the atmosphere ,”sprouting” on the paint. Pan paints on the other hand have been formulated to dry completely and have a disinfectant in them.
and
2. that letting tube paints dry completely produces “friable” paint. That is, it is not the wetting but the drying that’s the problem.
This is a more serious problem.
Friable paint will make it hard to not have little bits of dried paint in your rewetted paint unless you were to take the extraordinary step of grinding them as well. What happens is that the tiny granules of pigment regroup and form larger hunks as they dry. (I once in my naive days made genuine vermillion paint with the medium sold by Kremer (Gillot’s), and when it dried, I could not rewet it no matter what I did — even leaving it in a glass of water overnight. ) This suggest that they also put something in their pans (or leave something out) to allow them to be re-wetted without becoming “friable”.
It is this failure to be able to reconstitute tube paint to their original ground-into-small -pieces condition that makes some people claim that re-wetting dried tube paint does not produce as attractive a mark on the paper as the original. The mechanism for the inferiority of the wash is that the paint granules are not as evenly ground anymore.
Some paint granulates on the paper naturally and this is considered attractive by some people. However, friable paint granulates in an unattractive way with big pieces and does so whether you wish to have that sort of wash or not with paint that normally doesn’t granulated.
This has happened to me. I rewet paint that has dried on my palette by scrubbing it with a wet brush. This is wrong because it will wear off the hairs on the brush, but I’m in the middle of a painting having come back from a break, and for some reason I think I don’t have to wait for the paint to dissolve. Then I notice when I’m laying down a wash that there are hunks of dried paint sticking to the paper. They are hard to get off without marking the wash. There are usually only one or two of these large pieces at a time; and, in my case, it hasn’t been consistent across all the paint. I can see, if this were to happen more frequently, it would be a disaster.
semi-moist watercolors
There is now another category of watercolor paint that is neither pan nor tube. Yarka, the company that was created after the communist regime in Russia collapsed from six different government owned factories (canvas, watercolor, drawing materials, etc.) now produces a gummy watercolor for students and children in pans that remains moist and reconstitutes with “just a touch of a wet brush.” A 12 pan set has a list price of $8.99. But the point is that they are marketing this pan set of paint that presumably has enough humectant (water holding) ingredient like honey to keep from drying. How they handle the problem of mold, I don’t know.
Without advertising it there are more up-scale paint manufacturers that produce tube paints that, once squeezed into a pan, never dry. So I think this semi-moist paint might be more obvious in the future.
A little history
In this regard the history of pan and tubes is interesting.
Before pans or tubes watercolor paint had to be made by hand by the artist. Raw materials were bought by the artist at apothecary shops. In the late 1790 there were merchants (“colourmen”) who sold premade dried pigment in pig bladders directly to artists — the beginning of an “art supply” industry. At about the same time in London William and Thomas Reeves began selling dry, hard cakes of watercolor paint. In the beginning , before the paint could be used the cakes were ground with water in special saucers or mussel shells that came along with them. They were too hard to wet with a brush. This was called “rubbing out one’s colors.” We do this today with Sumi ink as in the illustration below.
This was very inconvenient and did not encourage the general public to take up painting.
Reeves began adding honey to their pans in 1780. Reeves pans were more convenient to sell and store and perhaps now could be wetted easier than before. The addition of honey was probably the key to their success because honey is a humectant — that is, holds water. Reeves always embossed his pans with a design. The pans revolutionized the use of watercolor by making paints easily available to the general public.
An American portrait painter living in London, John Goff Rand, invented the paint tube in 1841 but sold the rights to pay his debts. Winsor Newton began using tubes (made by someone else) in 1835. They also added glycerine to the watercolor paint that they put in the tube so that the paint could remain moist which became their “secret ingredient”. They also made dried pans but held the glycerine. As today, they kept the details of their recipes secret so what else they added we do not know.
Judy Terman’s advice would apply to Winsor Newton watercolor tube paint and would be following their suggestions for the use of their paint. It is difficult to determine whether her advice applies only to Winsor Newton tube watercolors or all manufacturer’s watercolor tubes.
Judy Treman’s studio practice
But first let’s see what Judy Treman does:
She puts some tube paint, presumably Winsor Newton, in a well on a palette, not in an empty pan, and adds an equal volume of distilled water and waits a half and hour. She does not mix the distilled water and the paint, but says that this seems to happen by itself with a satisfactory result. I find this to be the case. It is this paint/water mixture she keep wet. However, in my observations after a span of a few days some of the paint that has been dissolved in an equal amount of water, if he has not been used and stirred a bit, seems to separate into some fairly wet paint surrounded by what looks like medium. However, it readily returns to good consistent paint.
Treman never lets the tube paint dry by continuous spraying them and then storing the palette in the refrigerator at night. In this way she can make the paint last about 3 weeks before they develop some mold , so she recommends putting what you would use in three weeks in the palette wells.
(It occurs to me that one could put an anti-fungal in the distilled water that is sprayed to extend the mold-free life of the paint. I have experimented with spraying Lysol spray from pretty far away over the palette. It leaves a smell, but doesn’t seem to do anything to the paint. I will have to add to this paragraph when I see how long I can keep the paint going this way)
Well it’s been three weeks and one day and, in spite of my timid spray with Lysol, the Cobalt Violet Deep (Sennilier) had a gray bloom of mold on it today. It was difficult to get it out of the well because, with the other wells full of liquid paint, I couldn’t just tip the palette and let it run out. I am now experimenting with the rest of the palette, 17 paints that did not develop mold, by being more aggressive in my Lysol spray. I’ll keep you posted.
Several months have gone by with my using lysol and making sure that the paints stay wet and I’ve had no more mold. I also really like working with wet paint. I realize I used to have to scrub tube paint. Now, if I’m using some paint that isn’t in the palette that I have not been keeping wet, I put an equal amount of water in the pan or well and wait a half an hour. I get more paint on the brush and the intensity is stronger.
It is also worth experimenting with a palette that has individual containers that have air tight tops like the inexpensive “Color to Go” palette. See here. The caps are not hinged as in the “Possum Palette” which means you have to take them off a store them. I’m sure that I would lose some of the tops in a plein air setting. There is also a more expensive version more widely available called the “Possum Palette” with hinged tops. You can also just buy the containers with hinged tops from Richelson which they call “solvent cups”. All of the containers are watertight.
This sort of palette solves the problem of bring liquid paint into the field, and, perhaps, it prevents the paint from drying out so fast. The general opinion on WetCanvas is that they retard drying for a little while. No mention of whether it retards mold. Air tight containers can still develop certain species of mold.
Since Treman’s paintings are all about packing as many high intensity colors as she can into a painting (as she herself says), she claims that rewetted tube paints are not as saturated and never reconstitute to the consistency of diluted tube paints. This would be the result of what Winsor Newton calls “friability” of the reconstituted paint.
Clearly just rubbing a wet brush over dry paint will not produce a good paint and will blunt the brush. This is well known. Also clearly one wants to be able to dip the tip of a brush into paint that is liquid enough to receive it (not scrub away to get some color on the brush) whether you are using tube paint or pan paints. This is not what many people do. They rub a brush against dry paint and transfer a little bit of that paint to a section of the palette repeating the procedure until they have enough paint in a puddle on the palette. Sometimes they first put water in a cup-like part of the palette and then transfer paint. The paint is not liquid enough for the brush’s tip to go into the paint in the palette’s well or the pan and pick up a lot of paint.
Incidentally there is not enough room in a pan to put the necessary water in it if you fill it up with tube paint to follow Treman’s advice until it is at least half used up, so empty pans that you have filled yourself with lots of paint can not to be used in the Treman manor.
There is no question that fresh and dried tube paints can be made liquid enough to dip a brush into the well even if this is seldom done. What is at issue is whether dried tube paint can be reconstituted with water (or water and gum arabic) to the same quality paint as would be done by using fresh tube paint (and water).
While I’m at it, many modern tube paints for a variety of manufacturers do not actually dry to the same state as paint in pans. They have sufficient water holding additives to make them remain “gummy” for months, and this has to be achieved with a lot of honey or something like that. (Pure honey doesn’t dry, by the way). So modern tube watercolor paints seem to be formulated differently, very differently than they used to be (and differently than any of the recipes on the internet for making your own watercolor paint, for example, at Kremer paints.) But the question is: does that mean that tube paints should not be allowed to dry down to the gummy state or drier?
Bruce McEvoy at Handprint says that Sennelier and Blockx tube paints with the black caps do not dry and remain gummy. Boockx tubes in the white caps or Rowney Artists tubes, on the other hand, dry to a” resinous brick” that is very diffficult to rewet.
If Virgil Carter’s information is accurate that most paint suppliers use only one formulation for watercolor paint and the observation is correct that many modern tube paints stay gummy for a long time, then these other (e.g. not Winsor Newton) paint manufacturers use the non- drying formula (gummy) for pan paints and tube paints. If we accept the W&N critique of rewetting tube paints, it means that the pans of these other (non W&N paint manufacturers) should not be used and are inferior to Winsor Newton’s pan. That’s hard to believe, I know, but that’s where the logic goes.
This all hinges on the difference that can be seen between the fresh tube paint on the paper and the rewetted tube paint on the paper. I actually think I can see a difference now that I look. The fresh paint makes a wash or mark that is more uniformly colored and gorgeous. The rewetted paint makes a wash or mark that has more variation in it, not enough to qualify as granulation, just enough to compare badly with the fresh paint. It is a subtle difference that might not matter to most people.
When I raised this question on WetCanvas, a lot of people responded that they hadn’t noticed any difference between fresh paint and rewetted paint and were quite adamant about it going so far in one case as to propose it was a plot to get people to buy more paint. Unfortunately these are the same people who don’t notice problems with their perspective, composition, proportions, etc.
With regard to mold: mold spors are everywhere. They are floating around in the air. You can’t avoid them or remove them. They are not particularly in the water you use, therefore I don’t see what benefit using distilled water would be. Mold spores only grow if they get the right conditions: moisture, darkness, and warmth. Refrigerating a palette removes the warm condition but the paints are still wet and in the dark. Letting the paint dry would also be a way of avoiding mold. A good pan paint will dry rapidly, yet W&N puts more disinfectant in pans than tubes. Exposure to light might also be effective in retarding mold.
Honey , by the way, is not the source of mold nor does it encourages mold growth. In fact, honey is so thirsty for water that it sucks water out of mold thus killing it. It has been used as a wound disinfectant.
I’m in the process of making some of my own observations about rewetting tube paints and will add what I find to this post. One thing I have already found is that I have been filling my pans too much because I cannot add a 1 to 1 ratio of water to them as Judy Treman suggests. So I have changed my “studio practice” to that extent.
