Marble dust as a transparent filler?

[llawrence]

Ramesh, thank you for the report. Kaolin is one of the things I'm interested in trying out. As I mentioned before, I've played around with natural calcite. What I liked about it: it can make very bright tints of reds (and, to a lesser extent, yellows and violets) without cooling or desaturating them nearly as much as other whites do. The tint of cadmium scarlet and chalk was like no other color I've seen in oil paints. What I didn't like: the texture. Not at all what I'm used to, laborious to lay on and thickening to a mud-like consistency immediately, making it difficult to blend. I plan to try, among other things, precipitated chalk to see if it is any smoother than the natural stuff.

[AMIEN]

Ramesh, thank you for the report. Kaolin is one of the things I'm interested in trying out. As I mentioned before, I've played around with natural calcite. What I liked about it: it can make very bright tints of reds (and, to a lesser extent, yellows and violets) without cooling or desaturating them nearly as much as other whites do. The tint of cadmium scarlet and chalk was like no other color I've seen in oil paints. What I didn't like: the texture. Not at all what I'm used to, laborious to lay on and thickening to a mud-like consistency immediately, making it difficult to blend. I plan to try, among other things, precipitated chalk to see if it is any smoother than the natural stuff.

llawrence,

Precipitated chalk has an absolutely uniform particle size and is smooth and light -- sort of like the texture of the talcum powder you'd use on your infant's bottom after a diaper change. (That's fun, isn't it?!)

You will need to adjust the amount of binder or added mediums in mixtures with any chalk-like additives, of course.

[Ramesh Vyaghrapuri]

Sorry, still working with Kaolin (decided to regrind as I felt the previous mixture had too much oil -- it was the same consistency as my other handmade paints but I am learning that all of the first batch have too much oil).

Anyway, I made a paste this time (not quite putty -- it seems like marbledust makes a putty but kaolin only makes a fine paste) and tested it with the better handmade paints I have and some store-bought ones.

I have to say that the handling is different -- easier to mix, feels fluid to the brush but sticks without movement on the panel. When I made it into a putty, it worked well to thin colors and keep the tints bright but there was still a chroma change between paints extended this way and those that didnt. So, I decided to add a touch of stand oil and the paste looked much better. (It is surprising how much effect a small amount of stand oil can have).

Also, it is interesting that extending colors this way enhances the undertone (makes it look like some pigments are actually duotones).

And it appears like this is drying much faster than regular oil paint..

[AMIEN]

Sorry, still working with Kaolin (decided to regrind as I felt the previous mixture had too much oil -- it was the same consistency as my other handmade paints but I am learning that all of the first batch have too much oil).

Anyway, I made a paste this time (not quite putty -- it seems like marbledust makes a putty but kaolin only makes a fine paste) and tested it with the better handmade paints I have and some store-bought ones.

I have to say that the handling is different -- easier to mix, feels fluid to the brush but sticks without movement on the panel. When I made it into a putty, it worked well to thin colors and keep the tints bright but there was still a chroma change between paints extended this way and those that didnt. So, I decided to add a touch of stand oil and the paste looked much better. (It is surprising how much effect a small amount of stand oil can have).

Also, it is interesting that extending colors this way enhances the undertone (makes it look like some pigments are actually duotones).

And it appears like this is drying much faster than regular oil paint..

Ramesh Vyaghrapuri,

Thank you very much for your interesting and pertinent observations!