You can make significant impasto with putty on panels and have it be stable, but you want to be more careful on stretched canvas because the support itself moves over time. Egg yolk also makes the paint dry “up,” that is, on the bright side, and keeps it that way. With egg yolk, this makes a shorter, more fudge-like putty and is safer on panels. A putty with a little egg white in it is relatively elastic and thixotropic, basically meaning it makes more charismatic marks. If, for example you add a little egg white to stand oil, say 5 to 10 % and mix well you will get a very mobile material that paints out very thinly. The technical art history people feel that egg white was used by Rubens as a way to cut thick oil. We know that oil and water do not mix, so when a water based ingredient is added to a putty, there is a form of seizure or increase in density. The other option is a form of ground silica, this is what was done in Venice, everything from ground pebbles to ground glass, but silica does not help the paint dry or enhance its stability the way calcium carbonate does. Aluminum hydrate is used in modern paint manufacture but I recommend that you use a natural form of calcium carbonate as the particle basis of a putty. Calcium linoleate is formed by the interaction of any calcium carbonate and linseed oil and is not water soluble, meaning a paint film that is more resistant to humidity.

They also form a very stable and tough film. All forms of calcium are secondary driers, so these materials help the paint dry. Calcite is of course found in the work of Velazquez and the Kremer calcite 58120 acts like tiny ball bearings in the paint. There are lots of different marble dusts and they are all fine to use, not as fine or creamy as chalk but it’s not a big deal.

The best natural chalk I have found is the Kremer 58162, this is almost white in oil. It has been found in Rembrandt’s paintings, Vermeer, Chardin, and Cezanne. Manmade chalk is called precipitated calcium carbonate, and I agree that it absorbs too much oil to be reliable for painting. Natural chalk is sedimentary, limestone (whiting) or marble dust are metamorphic, and calcite is crystalline. There are lots of different types of calcium carbonate. I wonder if a little fumed silica in the mix (or AH maybe?) might create a useful compromise. Some people say the chalk putty is too sticky and stringy. The fumed silica (dangerous stuff, read about it if you intend to use it) apparently makes a gel when mixed with oil, but I think this is a relatively fat mix. Actually I have some of each on order as well as some fumed silica. The AH is commonly used as you have noted but it seems logical the chalk would be a better addition in underpainting for example. For this reason it should in theory yellow far less, there is also a historical precedent for it’s use an I might be wrong on this but I’m not sure the same is true of the AH. They list aluminium hydroxide as 33-55 g/100gms but chalk at 15-20 which I think is about as lean as oil paint typically gets. However according to the The Colour of Art Pigment Database the chalk is far leaner in mix with oil. Yes the aluminium hydroxide is used as a filler also. I think in essence they are all mainly calcium carbonate but I guess there is some natural variation which is of course true of many natural pigments. They stock a number of different chalks, marble dusts etc. Would still like answers to my grown questions though.Īllison, the Natural Pigments website is well worth a look.

It’s good, it’s bad, it’s good again, it’s wonderful…. ” 70% – and that is the ingredient I used – Alumina hydrate – so this means I can use it, and it is better than the chalk/marble dust? AGH!!!! I am so confused I think I now have bi-polar. VERY INTERESTING READ – which says “Pthalocyanine for example is such a powerful coloring agent that its use on the palette would be almost impossible without the legitimate addition of up to 70% alumina hydrate during manufacture. And then you say Alumiumhydraat is the real thing – so does that mean it is OK afterall?Īnd then side – sidbledsoe – sent me this link, Marble dust is chalk – both are calcium carbonate. Alumiumhydraat is a real thing and a most popular colorless additive nowadays! It can be more oil adsorbent and, therefore, more prone to yellowing. Chalk is a cheapest variation of Calcium Carbonate.

Putty meaning in painting