Haarlem oil

[Dan F]

I'm trying to learn about William Bouguereau's techniques and materials and found this article:
http://www.realcolorwheel.com/Bouguereau.htm
It mentions some materials such as haarlem oil and a drier called Courtrai, among others. Can someone explain these materials, and if they might make sense to use nowadays. Thanks.

[fechurch]

Siccative Haarlem was copal dissolved in spike oil. I have never used it, but some period writers criticized it for not truly promoting drying, but simply evaporated. I disagree. From my many experiences with copal, the resin does have a slight siccative effect on oils. And spike is known to promote oxidation.

I do ues Siccative Courtrai. James Groves, the varnish maker and painter makes it according to the 19th century recepies. It is exceedingly powerful. After 2 years of use, I'm still in the neck of the bottle. All modern driers I have tried required several drops for the same effect. It is pure black in the bottle and umber brown as a drop. Its blackness doesn't matter. A half drop is all that is necessary to make all colors dry in 8 hours. It dries faster in the heat. This is why Bouguereau used it in mediums as opposed to just pure. It's power is sufficient to make the whole medium drying without adding much color.

To illustrate its power, I have a story: I once ground a 50ml tube's worth of lamp black in nut oil. As you know lamp black dries extremely slowly. I added about 8 drops of courtrai to the 50 ml mass and it dries in a day no matter the thickness.


I'm not sure how safe it is to use driers . If you look at Bouguereau's work, it has that web-like cracking that conservators blame on driers. Frederic Edwin Church supposedly used courtrai, too. His earlier pictures and most alla prima sketches are in good shape, but most of his later paintings are very cracked.

[George O'Hanlon]

As a further note to fechurch's comments above, siccative de Haarlem was a highly variable product in the 19th century, so any modern recipe for it is so much guesswork at best. From literature, it appears to be a copal oil varnish dissolved in turpentine and/or spike oil, but what driers and the proportions of the different ingredients are unknown. It was a liquid drier, similar in effect to terebine used in the 19th century, so it would have been a highly diluted copal varnish.

Most likely the driers used in this varnish included lead and manganese, and were probably added in the form of lead and manganese resinate or rosinate.

Often these drying metals were added in excessive amounts and could be one of the reasons we find cracking in the paint films where it has been used. Preparing this as a modern-day siccative would require special attention to this detail.

[John Kennedy]

According to Max Doerner Siccatif de Haarlem consists of thickened oil and dammar varnish (does not mention any thing else in the mix) and when pure, is unharmful when used.

I would have to also mention that many succative, drying oils are salts soluble in oil made mostly from metal oxides, cobalt, and maganese and usually diluted for use with oil of turpentine. The obsortion of oxygen by fatty oils is accelerated by these oxides, thus drying oils much faster than normal. But, history shows that if not properly used and too much in volume to paint, causes deep, wide cracks, discoloration spots and cloudiness in colors.

Also, no succative should be used with colors that already dry quickly on their own physical make-up.

So, basically, a good mix for siccative de Haarlem would be what Max Doerner has discribed with the thickened linseed oil (stand oil) and dammar varnish. If you want faster drying time my books suggest that maganese resinate (I believe being more the modern siccative) using just a couple of drops might be your best bet, if this is something you really want to use and get into. I would definately try it only with due diligence and much experimentation befor trying it on any existing paintings.

Good luck and happy painting!

John

[George O'Hanlon]

Keep in mind that the Siccatif de Haarlem mentioned by Doerner and used in the 20th century is different from that found in the 19th century and used by such artists as Bouguereau.

In any case, there is no single formula for Siccatif de Haarlem, as it was a name applied to many different types of what were essentially oleoresinous varnishes containing metallic driers.