Over the years I've used different pigments and methods of extending the paint (Geneva Paints, Clove Oil, etc..) but I've never done any actual testing of different paints to compare drying times, opacity, colour, etc..
I am halfway through testing a large amount of paints and will be posting the results here as well as detailed photos so as to help other people out who are interested.
This is the method:
- PET-G sheets (nonabsorbent) painted with a layer of W&N Clear Gesso. This is an acrylic medium with silica particles for tooth. This Gesso is transparent and is less absorbent than white gesso and has more of a tooth.
- Lightly sand the dried sheets with a worn 600 grit sandpaper just to take off the rough parts and still leave a good surface.
- The resulting surface is the same as I would use for painting (except I would paint on a lightly sanded Aluminium Composite Material Panel).
- With an adhesive spray attach a printed paper to the back which contains details of each paint tested as well as an area to test for opacity and one for drying so it looks like this:
Each black box area will have two applications of paint to test for opacity, on the left straight from the tube, and on the right of the box when thinned down with walnut oil to a slippery consistency. I will then paint a strip above the names which I will use for drying tests.
The sheets will be stored in a box (not airtight) in the dark
in my house with an average room temperature of 20-22C. This is how I store my paintings and palette when I am working on a painting to lengthen working time. Once it is done I place it high up on a shelf in a room lit by indirect sunlight to dry properly.
Each day I will take a rubber tipped shaper and draw a vertical line through the swatch to remove the paint. I will record the day I can't erase a full line of paint through the swatch (partially dried) and when I can't pull off any paint at all (fully dried) I will record that date and not test that swatch again:
(Quick photo, not colour accurate or light checked)
For whites I have prepainted a strip of Golden Heavy Body Titanium White (Acrylic) next to the black boxes so that I can test for yellowing after a few months of drying in indirect indoor sunlight.
I am looking at paints of all grades, from student grade paints like W&N Winton, to mainstream artist grades like W&N Artist and Rembrandt, and up to more high end Schminke Norma and Michael Harding paints.
I will mostly be looking at opaque or highly tinting colours (Phthalos, etc..)
I will not be looking at fugitive colours (PR83, PR1, PR5, PY1, etc..), or pigments that are overall less lightfast or can vary from batch to batch (PY3, PR112, PR170, PR188, PY73, PV23). I will look at some cadmiums, and a bismuth yellow but Cobalts are out of my price range, as are paints like Old Holland and Vasari.
I hope this proves useful to others (as well as myself!)