Monday, March 14, 2016

How to Oil Paint, Choosing colors for oil painting -- Part 2 of 4

 
Art Instruction, Choosing Colors for Oil Painting -- Part 2 Paint Properties 

Many art colleges and universities have over the last years especially, focused their attention when instructing art students, on encouraging the students to work primarily on their creativity and to "express themselves". However this has meant that the actual materials they should use to express this creativity have often been overlooked.

As you progress your journey in becoming an oil painter, you may like / should try to learn a little about the various different properties that individual paint colours possess. Apart from the obvious properties to consider such as hue, value and colour, there are properties such as transparency, opaqueness, oil content, type of oil, pigment content and light-fastness of the paint colour. Also how fast they dry, their tinting strength and their consistency. Then there are factors of compatibility with other pigments. Lastly, and important too, some paints contain lead and care needs to be taken in working with such paints. Different manufacturers will mean the same colour could be slightly different from brand to brand also.

The most important property of a paint colour is it's light-fastness.

Colours fade when their molecules are broken down when exposed to the power of light, the shorter the wavelength the more the power the light will have. So UV light packs a punch. Some pigments are better at withstanding this attack. Iron Oxide colours and heavy metal colours, such as cadmium or cobalt can withstand UV light.

If you want to protect your artwork from fading, then it is best to choose colours with good light fastness properties and avoid displaying the painting in direct sunlight. This means - how likely is the paint to fade in colour over time. Quite a bad feeling if you see your beautiful portrait of a loved one fading into obscurity after a few seasons on the wall....So what should you do?
Look to buy paints with an ASTM (American Society for Testing Materials) rating of I (very light fast) or II (lightfast enough to use for painting).
If you use ratings III, IV or V then the colours will change in time and may fade completely. Alizarin Crimson is one of the paints that is best avoided as it is not light fast. A good alternative is Permanent Rose, also called Quinacridone Rose or Rose Lake. It is PV19.
Different brands have different notation. Winsor & Newton use A (permanent), AA (extremely permanent), and also the above I,II,III system too sometimes. Daler & Rowney Georgian brand use Permanence followed by *** symbols. Three stars is fine and four is best.

The next quality perhaps to consider is the quality, or pigment content of the paints.

Depending on the brand, most paints come in two grades, artists and students. Artists grade paints are made with the higher amount of pigment content and less extenders, and they produce stronger more vibrant levels of colour. They also cost a lot more in some cases! If you are starting out, it might be worth while to buy the student grades for now. The difference is not so noticeable, I have found, although the fact that paints can last a lifetime depending on your rate of working, and use of a colour, perhaps the better investment is to go for the more expensive brand when you can afford it. I use the best I can afford when I am doing commission work or work for sale.

For more tips about properties see part 1 , part 3 and part 4 of this article.

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