Making Valazquez medium for solvent-free oil painting

Chalk and oil paint in the wild, gamblin oil colour, 1980 student grade line.

https://gamblincolors.com/oil-painting/color/1980-oil-colors/

...In order to reduce the cost of oil colors, some manufacturers use gels and waxes to stiffen colors and replace traditional pigments with less expensive ones.

Our approach is different. 1980 colors are formulated with pure pigments, the finest refined linseed oil and marble dust (calcium carbonate). More affordable colors have been made with these three ingredients since oil painting began...

Emphasis mine.

I've a couple of tubes for art class as these dry faster than my M Graham studio paints.  I noticed the texture was more enjoyable for the 1980 paints than winton which is kind of weird to work with as all the colours behave the same (oil paint shouldn't as each pigment is chemically different).

as part of the glazing experiments I mixed up some limestone calcite with regular linseed oil to make a stiff putty and added them to a few of the underpaintings.  It was about 10% putty to paint.

This sped up drying time a bit and helped the transparent colours behave less slippery when painting.  But still kept the transparent nature of the paint.  

As I was doing the glazing about a week later, I didn't notice any difference in the experiments with calcite added and the ones without.  I suspect if it was sitting a long time between layers, like a few months, that the difference would be more noticeable.  

I don't like using my stand oil calcit putty for underpainting.

Yes, mixing with the white makes it nicer to work with and a touch transparent.   But it dries slower and shiny compared to no additive, due to the high amount of stand oil.

I think it's time to make a tube of underpainting like one of the previous mixes I tried where the black and white chicken dried too fast.

About 2:40, she mixes in some chalk to modify texture and drying time.

My second batch that I tubed started to separate and oooze oil everywhere.

That could be because I didn't mull it much.

Conclusion I draw from this is that if I'm not mulling, make it fresh just before use

from here

Extender Medium, previously called Impasto Medium, is essentially colorless paint made with inert pigments in linseed oil. It is intended to be used as the name implies, to extend paint. It is made from marble dust (calcium carbonate) and barium sulfate which are typically used as modifiers for oil paint to improve feel and dry time. When used in larger amounts, these pigments are categorized as fillers, as in the case of student-grade oil paints.

Extender Medium is a translucent, pale grey paste that has a similar consistency to most of our oil paints. It has a very low tinting strength and only slightly lightens and changes the sheen of most colors when mixed in. An ideal use for the extender Medium is when you want to mix a larger quantity of straight paint and don’t mind a slightly less saturated color or a muted sheen. Using mixtures made with Extender Medium can be a very cost effective way to cover a lot of surface area. Underpaintings are a great opportunity to use the Extender. It can also help mix certain tints and colors that would otherwise not be available simply with the addition of white or other tube colors. A normal brushed out layer dries in about 3-4 days.

Looks promising.

And pretty affordable at the local art shop

This artist mixes their own calcite medium with rublev chalk and linseed oil of a ratio 2 powder to 1 oil.

https://workshops.kimberlybrooks.com/p/oilpainting

Online class specifically for the kind kind of painting I seek.  And at a cost above half my monthly income.  It's out of my reach, so I keep experimenting.  

It sure looks amazing though.

Marble dust painter spotted.  A new channel and one to watch to see where they go with this.

Hi R Ranson, hope your painting is full of fun and inspiring moments.
I have been reading some of this post and decided to reply before reading further lest I forget to reply.
Supposing one was to grind the limestone in a mortar and pestle if possible or a roller mill...,
and then that person was to take all that ground up rock and dust and wash it such as those who make their own clay by settling silt from the upper portion of the water...
And then let the water evaporate in the sun thus leaving the fine powder form as a "cake",
Do you suppose that fine powder or "cake" could then be milled or mortared again (once dry of course)?
Would that meet the level of fineness or microns you could use in your medium? Or might it be too fine?
I have not tried this yet. If you or others may attempt to do so, please share with us all both your successes and failures.
I for one would like to know if there might be anything learned from the process and if it has helped others,
Thank you for your posts. I will continue reading them now. Have fun and Good Luck!

That's a really neat idea.  We don't have limestone here (it's a bit of a geological island on our island).  So I couldn't try it, but I would love to hear how it goes.  You might be on to something.

Historically, it looks like they would use mostly wasts products from sculpture or other industries we don't have in abundance now.  

...

The other day, someone bought me high end gesso (the dollar store ran out of my normal stuff) and I was shocked by how gritty it is.  It's easily more gritty than the stuff I've been playing with.  This is usually caused by the same calcite used in the medium.  It's interesting to see what real gesso feels like.  But I don't know enough to say if it's related to my quest or not.

I honestly don't know yet and may have to try it myself.
Now where did I place those home depot style limestone rocks I pulled from the garden path or were they walmart style?
Or perhaps crushed shells or diatomacious earth such that the romans used to use for forming the mixture of concrete?

I suppose your 'Gesso' is as good as mine. lol I hope it works.

From The Artist's Handbook of Materand Techniques by Mayer.  First edition, 1940/41

Entries of note
Diatomaceous earth
Chalk
Marble dust (note, p269 is in the mortar section of mural painting)
Silica

From the same.  P90 and 91

Inert pigment

https://www.kamapigment.com/kama-products/pure-pigments/inert-pigments-fillers/calcium-carbonate-chalk-x-fine-3um-pw18.html

Best chalk dust for making the medium so far.  Although I bought it from a local store.  

Also known as Meudon white, marble powder, or Spanish white, this product is precipitated chalk powder. This grade (the most popular) is primarily used in the manufacture of gesso and other coatings for painting.

Chemical Formula: CaCO3.
Colour Index: Pw 18
Average Particle Size: 3 µm (microns)

It's very smooth when blended with oil and dramatically increases transparency of a paint when mixed 20% medium to paint.

I keep seeing references to Constables paint box having a lump of gypsum in it when he died (cause of death not related).  There seem to be a lot of theories as to what he ussd it for.  But also, a lot of variation at to if it was limestone, gypsum, or chalk.  

Constable mixed a lot of his own paints on location, so I can't help but wonder if this was related to adjusting the texture or qualities of the paint or if it was just a nice rock he found on the ground and he kept it because it's lucky or something.

Observation

If more than 20% calcite medium to paint, there is a noticeable value shift or sinking in, as the paint dries.

However, there are times this is useful, like increasing the transparency in the shadow area.

This value shift is more noticeable with darker colours and earth pigments like umber which have a strong chance of sinking in anyway.  

It returns to the proper colour with oiling out. Varnish should do the same, but it is possible we need to apply oil and let it dry before vanishing.   A good experiment would be gloss vs matt varnish.



In the picture, beside the red jug the wall colour is oiled out and returned to normal whereas the rest of the wall colour has lightened as it dried.

Another thought, we could use stand or bodied oil in the calcite mix to limit the sinking in.  But as this is lower layers of paint, I didn't want to risk too much gloss, making the surface harder to add future layers of paint.

I also want to keep the drying time consistent and predictable so I wouldn't break the flexible over less flexible rule (fat over thin, slow drying over fast).  Future layers have less calcite and more oil.  


Thinking more, the solution is not to exceed 20% calcite medium to paint unless there is a very specific reason.

https://justpaint.org/on-the-yellowing-of-oils/

The next two variations, which include the addition of barium sulfate or precipitated calcium carbonate, become increasingly less yellow while also showing a corresponding drop in oil exuding to the surface or out the sides.  

Although this study is still young and inconclusive, it suggests that extender pigments like calcite might decrease the way paint yellows as it decrease the amount of excess oil that rises to the surface as it cures.  Aka, calcite helps bind the oil better than pigment alone.  Possibly.

The study needs about 100 years more to be conclusive.

But it would be interesting to do a home experiment of titanium white and yellowing, including 1980 (calcite filler) and calcite medium as well as control groups from the tube.

Mixing calcite medium for impasto and improving transparency.

Gives a good view of the texture.   Although, seems a bit soft for impasto in my expierence, I also know that calcite varies in how it behaves, so it might be just right for him.

I'm feeling very much like I nailed this calcite thing.  Or at least understand the basics.
Here is a summary of where I am at, at this time.  I'm sure there is more to learn so I'll post observations as they occur.   It's a comfortable, safe, and affordable medium and most importantly, customizable to the situation.   I'm using it in most painings these days.



It helps to think of it like a paint with a moderately fast drying time (about the same as most earth pigments, but not as fast as raw umber or lead), high transparency, and matt or gloss depending on how we mix it.  Basically it's paint with PW18 pigment (Chinese white) which is transparent in oil.  

The Valazquez medium sold by rublev is fairly high gloss, or so I've heard from painters who used it.  But that uses mostly stand oil, so it's good for upper layers of painting and glazing.  It's easy to mix the calcite with linseed oil or even use coarser calcite for even better adhesion of the next layer.  

Underpainting and first layers.

Mix stiff paste of linseed and calcite.  Mix into paint up to 50%.  Use with fast drying and moderately fast drying pigments.  Improves drying speed by about 20%.  Increases transparency so keep that in mind when choosing an underpainting colours.  

I like this on a yellow ochre midtone gesso, raw umber and white to block in the big lights and shadows.



Options:
- alkyd
A few experiments adding M Grahm Alkyd walnut medium to mix the calcite paste have given me the conclusion that there is a lot of potential there, but not so much for me.  Too much alkyd makes the paint glossy and resists the next layer of paint.  Too little and it doesn't do any benefit to the drying time but is more expensive than linseed oil.   It would take a while to find the Goldilocks spot.  But I don't like the sticky texture that Alkyd medium adds to paint.  Like extra drag... I don't know how to explain it.  Alkyd medium makes paint feel sticky to me and I don't likes it.

- coarser calcite
Using coarser ground calcite makes a very slight texture to the paint that makes it easier for the next layer to grip to it.  A lot like good quality gesso has a bit of "tooth" to it.   Too coarse and it feels like painting with sand.

The coarse or fine grinds also appear to influence drying time.  Coarser appears faster.  This needs some experiments to be certain but it makes sense logically.

Regular painting

This medium is lovely for changing the flow of the paint.  I can mix up a stiff mixture for greasy paint, and thinner mixture for stiff paint.

For this, I find no more than 20% of the medium to paint is best.  Less is better.  

These layers do best with the finer calcite, usually sold as PW18 so it has a similar texture to the tubed paint.  

Although it won't make an opaque paint transparent (just choose a different pigment) it does add a tiny bit of transparency to opaque paints so the under layer will either add glow (if white underneath) or add depth (if raw umber or whatever your dark in your underpainting underneath is).  

Where it shines is increasing transparency to already transparent colours like ultramarine.  

The picture above, the woman has a blue skirt.  So I put the first pass with just ultramarine and calcite medium to almost glaze.  The next layer has some white to bring back the highlights, but mostly just the ultramarine calcite mix for the rest of the skirt.  Unfortunately the glow doesn't show up on camera.  But if I was to paint this normally, I would have to mix colours in with the ultramarine to darken it.  Instead, the underpainting dark is doing the work for me.


(not finished or varnished yet - so there is some sinking in and the glow won't show on camera anyway, the wall and face both get improved after this)

It's like a gemstone where the light enters the paint layers and reflects back.  If the setting of the ring is shiny or white, the gem glows.  If it's dark or tarnished beneath the stone, the gem looks dull and can even seem to draw light into it.   I'm very happy with these results as it looks like my memory of the national gallery in London (although this painting isn't there, they do have some from that time).  

For this painting, there is a lot of scientific studies with pigment analysis and the like.  I tried to be as true to the original as I could with the budget and resources I had.  If I had to substitute pigments, I tried to match not just the colour (hue) but also the other pigment properties like transparency, dry time, etc.

Regarding calcite, the analysis of the original and the papers I read all mention calcite in the different layers - especially the under painting.  All of them dismissed this as contamination, disreputable pigment sellers, or were simply confused why Vermeer would bother with calcite in these layers.  It's a low-cost filler that modern paint makers use - so calcite is viewed with distain in our modern eye.   This is one of the reasons I choose this painting - because we have an approximate ratio of calcite to other pigments.  I followed this as closely as I could while compensating for modern pigments.  

I feel strongly it worked.  

But it also required thinking of the painting more like watercolours than like modern painting.  Thinking about how light will penetrate or not depending on the mix.  Not just thinking about the colour: hue, saturation and value like modern colour theory, but thinking of paint like it's a real, physical thing that interacts with light.  I think this is what's missing in a lot of modern paintings.  

Um, main paint layer options
- changing the kind of oil changes the dry time and gloss.  For top layers and glazes, I like to use a mix of about 2:1 (two parts walnut oil to 1 part stand oil) to make the putty as this has a nice glaze.  But it's a pain if I have to paint over it.  When in doubt, use artist grade linseed oil.

- this won't teach a dog to lay eggs.  
This medium shines when combined with the understanding of how the individual pigments work.  Dry time, transparency, etc, might change slightly, but not significantly.  Choose the pigment correct for the situation, then add the medium to it.  

Likewise, we still need to consider the golden rule of "more flexible over less flexible" when it comes to oil paint.  This medium isn't fat or lean.  It's basically a transparent, moderately fast drying paint.  It's behaviour in drying and cracking is about like yellow ochre.  If using it in later layers, I use less calcite medium or I change to walnut oil if it's going on top of a slow drying layer.  

Future areas i want to explore include calcite as impasto medium and I've had some luck using it to improve the behaviour of cheaper oil paints

Wow, R, you’re getting some nice paintings!

I’m not a painter, and I don’t know if this is common knowledge.  I had an assembled ashford spinning wheel to finish, and I followed up on a mention of shellac.  It’s a resin excreted by an insect.  You can buy it in flake form, just dried bug stuff.  You dilute it with ETOH.  It comes in different colors.

It dries quickly.  When you put another coat on, prior applications can be re dissolved.  It’s transparent and dries glossy.

When you were describing the attributes of your new medium, it was a lot of the same language as shellac.  Not the same qualities, but interest in the same things.

Just in case it’s useful information…

Very neat.  I'm learning more about shellac this week in furniture and oil paint.  When it Oand distilled alcohol) became available in europe, it was used with some colours to increase glow.  But the details aren't clear how.  

I also am about to experiment with some old chairs as we can clean it by melting the shellac with alcohol and rubbing it around again.  This should help me learn more about it's behaviour.

Does it darken with age?

I don’t know about darkening with age.

Did you buy premixed commercial shellac?  To extend shelf life, they may have added some weird or toxic gick.

If your old chairs are shellacked you could get the old shellac off with just high proof ETOH.  Do your old chairs appear to have darkened?

Were you able to find shellac in your region?  I had to order on line.  Best place I found was “shellac shack”.  (He is located in Oregon so the shipping is pretty quick for wet coast and for Colorado). The man there was very helpful on the phone and has lots of information on the website.

He would probably be quite generous with his experience.

Shellac is used in foods and medicines.  Doesn’t seem like a dangerous substance.  The alcohol you dissolve it is is probably more risky!

With furniture, there is usually a need to remove the old shellac as there should still be lots on there.  I've been told to wipe the alcohol all over and it redistributes the old shellac which is, I'm told, usually better quality than anything we buy these days.

The flakes are easy to buy here, but not artist grade, those i probably need to order from an art store.

Love this. I made a note to read it later as I'm checking emails with morning coffee on the porch before I get in the greenhouse!
This makes me think of the time my friend Madeline and I did a Crape Myrtle draw down! We were definitely amazed at the result!

Can't wait to have more time on the homestead for art. Ive been thinking about my future pottery barn and sculpting studio waaaaaay to much this spring!

Hope y'all are well.
Dustin