Making Valazquez medium for solvent-free oil painting

I would love to buy some Velazquez medium from Natural Pigments, but life and complicated things and a bit of stubbornness prevent me and says I can make my own much easier.  

So I'm gonna try.

And maybe, just maybe, when I figure out how to make it, I can adjust it to match my painting style and have my very own  customizable solvent free medium.  

What is Velazquez medium?

It's a combination of Calcite (calcium carbonate CaCO3, also known as marble dust, stone dust, or chalk in artist circles) and flax (linseed) oil put in an easy to use tube that won't dry out quickly.

Finely ground calcite in bodied linseed oil. Use to extend paint without altering its consistency. Softer than Impasto Medium, makes colors slightly transparent allowing greater control over tints without whites.

Basically, a medium in this context is something we add to the paint to make it behave in a new and exciting way.

And lucky for me, I've just finished reading the book The New Oil Painting by Kimberly Brooks which is all about solvent free (aka, traditional) oil painting.  It goes into detail about what each element of oil painting does so we can make our own choices about what mediums, if any, we want to use.  Brooks also is a huge advocate for using calcite and oil to make a medium for oil painting that replaces just about anything a solvent might do.  

Here is a video interview with the author and about the method of painting solvent free

although it doesn't go into as many details as I would like about the calcite medium.

I've been playing around with the idea and had some successes.  And some less successful adventures.  
The plan is to document it here and hopefully someone reading this will have some ideas on what to try next.

Arming myself for this adventure with some tidbits from The New Oil Painter.

Calcite - (CaCO3 Calcium Carbonate)  Sometimes called chalk, stone dust, marble dust, calcite or whiting.  Three main types of Calcium Carbonate used in painting are metamorphic (marble), sedimentary (chalk), and crystalline (calcite).  

This has been used in art since at least Greek and Roman times.  Calcite becomes transparent in oil and can make even the most opaque colours more transparent.  The different kinds make slightly different effects, but are otherwise interchangeable.  Marble dust tends to be whiter and more opaque.  Chalk is more thixotropic (it stiffens at rest and becomes fluid with motion).  (paraphrased from The New Oil Painter)

And here is the chalk natural pigments sells for this purpose

Calcite is a brilliant white, fine whiting (chalk) for making grounds and adding to paint. Our whiting is dry ground from limestone deposits. Use this whiting to make chalk grounds and for adding texture and body to paints.

This is apparently one of the best sources for it, but as explained, life is complicated and I can't get it just now.

The finest whiting for making brilliant white chalk grounds. Our whiting is dry ground from limestone deposits in the Lucerne Valley, California. Dry grinding limestone reduces it to a powder without destroying its particle structure, which is essential in making strong chalk grounds and providing tooth on the surface of the grounds. The larger particle size of our chalk (when compared to precipitated chalk) keeps oil absorption low, which is ideal when adding it to oil paint and mediums. In painting grounds, it makes a durable surface with tooth for egg and casein tempera, distemper, encaustic, and oil paint.

Limestone (calcium carbonate CaCO3) is a type of carbonate sedimentary rock that is the primary source of the material lime. It is composed mainly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate.

The Lucerne Valley limestone district contains enormous high-brightness, high-grade calcite limestone reserves. The limestone district lies in the California Transverse Ranges of Southern California. The district extends for about 40 kilometers along the north slope of the San Bernardino Mountains overlooking the Mojave Desert. About 5% (12-thousand hectares) of the San Bernardino Mountains is underlain by Paleozoic carbonate rocks. This carbonate stratigraphic section averages about 1,500 meters thick, with white high-grade calcite limestone units ranging from 15 to 30 meters thick.

Add ground calcium carbonate to oil colors and mediums to create textural and bodying qualities to oil paint without affecting the color. Ground limestone has a little color in drying oil, so it can be added to oil paint without affecting the tint of the color.

And since I'm seeking a local alternitive, here is what I need to know.

Median Particle Size 11.5 microns for the fine.  3.5 microns for the extra fine.  

The chalk is considered an extender pigment and here is their article on how to use them.

In this video they show three different types of extenders mixed with refined linseed and bodied linseed oil.



They also compare it to the Valazquez medium and talk about how that is made (chalk and a mixture of stand/bodied oil and linseed oil)

But they don't mention the ratio.  

Before I knew all this, I thought dust was dust so I bought a kilo of "Fine Marble Dust (0-160μ Average diameter: 30, Bulk Density: 1.1 / packed:1.5)"

The goal is to have the micron size 3 to 11.  This is 30, which seems a bit too big.  Maybe it will work?  

SPOILERS: it sort of worked.  

A different example of mixing chalk foil for painting.

https://www.artcons.udel.edu/mitra/forums/question?QID=809

This discussion suggests 20 microns is the largest partical size recommend.

I asked at the art store today if they had any marble dust.  They seemed a bit offended and started to educate me that since it's an art supply used with rabbit skin glue, .... afraid of the poor little bunny lecture, I interrupted and told them it's also a common ingredient in solvent free oil painting without all the toxins.  That changed things and they called around to see if they could get some.

No luck.  None of their current supplies carry it.

Sigh.  

There was an idea that I might go to the place that cuts marble countertops and begg for dust there.

https://maiwa.com/products/calcium-carbonate?_pos=2&_sid=91c2bd38a&_ss=r&variant=47800927486264

Looks like it's used in dyeing too.  But no info on particle size.

The extra cost for the assembled product might be due to size filtering. Small size filters often have to be replaced instead of cleaned. 20 micron and below are pretty common for water and fuel filtering purposes.

It used to be quite a common ingredient in art supply as Calcite/chalk/marble would be used for everything from making gesso to polishing statues.  It's also a common ingredient in paint making.  These were all pretty finely ground.

I remember seeing lots of different kinds of dusts in art shops as a kid. It seemed like art supply shops sold more dust than paint.  I was told then that it was a waste product from other industry (counter making mostly) that would be sorted into different grades.  The waste product makes a very fine dust and the big issue was sorting and bagging.  But a machine did all that back then.  

But I think modern day artists have grown to love conveniences and pre-mixed mediums.  I don't blame them as the shops in town are selling to students mostly and when we are learning art, we don't want to fuss about with stretching linen or mulling paint.  We just want to make pretty marks on stuff.

And yet, I also wonder if there's something I'm missing about Calcite as there seems too be a hesitation when asked if a shop can get it in.  And yet, they are happy to have a wall of solvents and oils available for people of any age to take home.  

Today's experiment was with the coarser calcite/marble powder and a mixture of linseed oils.



I put a palette knife worth of marble powder on the palette and mixing in linseed oil one drop at a time until it made a crumbly paste.  Then I mixed in 2 drops of stand linseed oil which has a thick, honey quality.  The nifty thing about the stand oil is that it made the paste way smoother than previous experiments with just regular linseed oil.    Those tend to be quite gritty, but this has a smooth feel like paint.  A tiny bit of grit texture, but not so much it bothers me.

Why am I trying it today?  Well, I'm using palette grey (the colour of all the leftover paints left on the palette mixed together - today it's blue) and today it got quite runny as I had quite a bit of binder separation in the paints and left the extra oil on the palette.  The thing is, I want to use it for the starting mono-chromatic layer for a new painting, so it needs to be less greasy.  This seems to have done the trick as I mixed it in to each pile as I went to get a consistent texture between the colours/values.  



The paint I started with was too runny to the point where it made an expanding puddle.  Now it sits like well behaved oil paint.  Very happy so far.

Now to try painting with it.

This is a nice medium.  I'm able to get the right texture and smooth application of paint.  

After an hour, the brush looses shape due to the grit in the bristles. I'm guessing this is mostly from the calcite being too coarse i wonder if mulling would do the trick.

It's also drying a bit fast for my preference.   I might try with walnut oil next time.

Here we are.  It took two painting sessions to finish.  One yesterday afternoon/evening.  And half an hour this morning.


(for some reason my camera couldn't "see" the painting properly and either made weird patterns or turned it a funny colour.  It looks much better in person)

This is just the under painting.

Observations about the calcite medium
- that grit in the brushes is getting me down.  If I could get finer ground stuff, I think it would behave more like paint and less like grit.
- it dries super-fast.  The stuff I did last night was too dry to blend this morning.  But I am painting in a very fine layer.
- I bet I could play around with the stand and refined linseed oil ratio to make it more smooth like the commercial Velazquez medium.  

Do you have a way to sift the calcite more finely, so you can maybe put just the grit into a mortar & pestal, to grind it finer?

Carla Burke wrote:Do you have a way to sift the calcite more finely, so you can maybe put just the grit into a mortar & pestal, to grind it finer?

Filtering sounds hopeful.

I don't have a non-food safe mortar and pestal.  would I need one that is made of something stronger than marble?  

I don't think so? Calcium stuff is typically brittle enough to crumble pretty easily.

Carla Burke wrote:I don't think so? Calcium stuff is typically brittle enough to crumble pretty easily.

The dust I have now is marble dust.  I don't know much about it other than that.  I'll see if the thrift shop has something to grind it next trip.

I got a random bag of white powder from the local agricultural supply shop.  It's some sort of calcite ground like talcum powder used for marking the ground?  Maybe like a soccer field?  

Can't wait to try it.

interesting article on extender pigments for making solvent free mediums like this.

Although some of the information seems to contradict other stuff I've learned so far.  Or at least seems to. I suspect as I learn more about how light interacts with pigments, things will make more sense.

But for now,

Comprehensive Classification of Extender Pigment Particle Sizes
Very Coarse Pigments
Micrometer (µm) Range: >100 µm
U.S. Standard Sieve Size: Particles retained on No. 150 Mesh (106 µm)
Descriptive Term: Very Coarse
Visual Reference: Comparable to coarse sand or table salt crystals
Pigments of this size were common in historical periods before the advent of fine grinding tools. Artists like those from the medieval and early Renaissance periods would often use pigments with very coarse particles, producing heavily textured surfaces with noticeable granularity, which enhanced certain tactile effects and luminosity in their artworks.

Coarse Pigments
Micrometer (µm) Range: 75–100 µm
U.S. Standard Sieve Size: Particles retained on No. 200 Mesh (75 µm)
Descriptive Term: Coarse
Visual Reference: Comparable to granulated sugar
As grinding techniques improved, pigments began to be processed more finely, though coarse pigments remained in use for specific applications. Coarse pigments are associated with visible brushwork and thick impasto techniques, often employed by painters aiming to emphasize texture and bold color.

Medium Pigments
Micrometer (µm) Range: 45–75 µm
U.S. Standard Sieve Size: Particles retained on No. 325 Mesh (45 µm)
Descriptive Term: Moderately Fine
Visual Reference: Comparable to beach sand
Pigments in this range are characteristic of traditional paint formulations used from the Renaissance to the 19th century. They offer a balance between texture and smoothness, making them suitable for both fine detail and broader applications. In modern artistic practice, these are still favored by those who prefer some degree of texture in their paint.

Fine Pigments
Micrometer (µm) Range: 20–45 µm
U.S. Standard Sieve Size: Passing through No. 325 (45 µm) and retained on No. 635 (20 µm)
Descriptive Term: Fine
Visual Reference: Comparable to flour or fine sand
Fine pigments are well-suited for techniques that require moderate texture, such as classical oil painting, fresco, and specific industrial coatings where some degree of opacity and visible brushstrokes are desired. The particle distribution in this size range contributes to a slight granularity, offering greater color opacity and enhanced surface coverage.

Extra-Fine Pigments
Micrometer (µm) Range: 10–20 µm
U.S. Standard Sieve Size: Passing through No. 635 (20 µm)
Descriptive Term: Extra-Fine
Visual Reference: Comparable to powdered sugar or baking flour
Extra-fine pigments are optimal for techniques that demand a high degree of smoothness and reduced texture, such as fine detail painting, precision coatings, and conservation work. Their size range allows for better pigment dispersion, facilitating thin layering and achieving more even, transparent color applications without visible grain.

Ultra-Fine Pigments
Micrometer (µm) Range: 1–10 µm
U.S. Standard Sieve Size: Not applicable; below practical sieve classification
Descriptive Term: Ultra-Fine
Visual Reference: Comparable to copier toner or airborne particles
Ultra-fine pigments are critical in high-performance applications, including photorealistic painting, digital printing, and advanced thin-film coatings. Their size enables exceptional light scattering and superior color uniformity, allowing artists to create highly transparent glazes, achieve fine details, and produce even color films with minimal surface texture. These properties make them indispensable for cutting-edge artistic techniques and specialized industrial processes.

The Calcite from the agricultural supply store has some promise.  It is much finer than the stuff I got from amazon.  It behaves almost like cornstarch in that it's runny and crumbly at the same time.



Not the best photo, I'm afraid.  but it gives the idea.  

The experiment with the marking powder from the agricultural shop.

I began by marking out the painting in charcoal pencil because, mostly because procrastinating.  



I haven't had much time to use oil paints these last couple of months, so I was nervous.  

The agricultural powder could be limestone or marble dust, it's hard to know.  It is a lot finer than the stuff from my previous experiment.  When mixed with mostly walnut oil and some stand oil (4:1 ish), it made a paste that is just like what we get with corn starch.  

at first, I'm mixing too much medium in with the paint.  For the background, I'm using almost half medium (recommendation is 20%) in hopes of getting the effect I want (I didn't) and seeing how the paint would stand up to it.  Also, I had a lot of binder separation in the paint, so this calcite paste helped to stiffen it.  



For the chicken part of the painting, I stuck to about 10-15% calcite paste to paint.  

This was enough to influence the texture and expand the paints.  Unlike the last dust that smoothed the texture of the paint, this dust seems to bulk it out.  It might make a nice impasto medium.

It also started to dry fast.  Usually I can start a painting one morning and work on it all the next day and get lots of blending and stuff.  But with this, I applied the black of the feathers around noon, and by evening, I couldn't get it to blend properly with the white.  (notice the softness of the head feathers vs the body feathers).  



The next day, some of the places where the paint is thinner, are already touch dry.   It's also very matt and "sunk in".  


For my style of painting, more stand oil would go well with this powder.  That, and using less medium.



and like the other powder, it's really embedded itself in my brushes and is hard to clean.  Glad I'm using cheap brushes.  Given that paint is just powder and oil, there must be some way to get this powder to wash out easier from the brushes, but with a regular oil dip, it's having trouble.  Perhaps mulling the powder into the oil would be the next thing to try.  

Also, in my defense, these aren't colours I've worked with before.  My regular paints are hidden and these are backup paints.  Although, I quite like that yellow.  

Preliminary experiments with murphy oil soap as brush cleaner appears to solve the grit build up that I was getting with the oil brush dip.

You did see that Natural Pigments sells the marble dust in 3 grades, the finest of which is 1-10um.

https://www.naturalpigments.com/marble-dust.html

Long time acrylic painter here, just getting into oils and had just ordered that book, the new oil painting, from the library when I saw this thread.

Very interested in your experiments, carry on!

Excited to hear of someone else playing with this idea.  Please share your experiments.

Getting the dust from the usa is proving problematic rigt now.  Shipping is so high, but free shipping is worse as it means buying so much I have to pay unknown amounts of brokerage and duty on top of regular taxes.  

One day I'll get some from them, but gotta save up for it.

Random thoughts

What other dusts would be good for this experiment.   Calcite has known qualities,  but would they have had pure dust back in the day or would natural rocks be mixed in?  

Quartz has shiny stuff in it.  How would that react?

All sorts of ideas to try.  Just need to find where to get it.

Looking at the safety data sheet for this calcite dust I got from the agricultural supply shop, it's ground calcite from naturally occurring limestone.  There is a 0.4% chance of silica quarts, but the rest is calcite.

I bought a 30 kilo bag, but if it doesn't work, I can use it on the garden.

It's an irritant if breathed in dust and avoid eye contact. The silica makes it have a small chance of causing cancer if inhaled.

I decided to make a bigger batch so I don't have to deal with mixing powder before painting.



A very exciting addition to my studio - big stone slab!  This is awesome to work on.  

My ingredients today are
fine calcite powder
stand oil
refined linseed oil
rosemary essential oil



I'm also going to try out another new toy. My muller (glass thingy with handle)
I say "new" but really, it's been here since spring and I just haven't played with it yet.



I made a pile of calcite powder and added stand oil to it at a ratio of 3:1 (calcite:stand oil) to make a stiff paste that can stand on its own. Almost like well kneeded bread dough.

I also added a drop of rosemary oil because I felt like it.  It's used in mediums as a solvent and according to the book The New Oil Painting, is about 4 to 10 times stronger than clove oil as solvent.  And since stand is almost always used with solvent and rosemary is one of the few that don't make me have allergies.  I don't know.  It felt like the thing to do.  A preservative, solvent, smell... let's try it.  

Although, to be clear, used as solvent seems to be different than an actual solvent.   From what I can tell, this would be an ingredient in a medium, not a solvent like we know today... so I might be confusing or equivicating when it comes to describing how rosemary oil works.



Here we are after adding some refined linseed oil.  About 3 or 4 drops at a time, mix it in.  I kept going until it looked like the valazquez medium in the video.



From here, I divided it into small batches and started mulling.  

Mulling is really, really hard.  I don't think I did it anywhere near enough, but it did change the behaviour of the medium.  I imagine if I had to mull all my paints, I would have very greasy paint because boy... I can't even describe how much my arm and wrist hurt.



How I got it into the tube, I'm not sure.  It was a mess.  I put it in a palstic bag, cut off the corner, and thought I would squeeze like icing.  It's a good theory but the bag only fits in the back end about a quarter of an inch so all the medium is up one end with a big air pocket in the front.  Need another way.  

But I'm tired and the chickens need singing too, so we'll find out if this works later.  

A bit about this Stand Oil of which I speak.

Calcite sun oil (CSO)

I admit, I've been avoiding this as I find the videos difficult to understand. But the person is passionate about their discovery.   He bases it on museum analysis of old paintings like Rembrandt that include calcium carbonate in the paint layer.  So I think there is something here.




Medium prep starts at 15:30, before that is some nifty stuff about oil prep which I'll come back to if my painting skills are ever good enough.

https://www.calcitesunoil.com/index.html isn't looking good.  I hope to run it through the wayback machine when it's back up.  But some of the pages remain.   https://www.calcitesunoil.com/BOOK.html

https://patents.google.com/patent/US7141109B1/en is the patent mentioned in the video.   It has the ratio of dust to thickened oil at 3:1.

Something I noticed from the video is that he is making a much stiffer mix than the rublev videos.  It's a lot like my first experiment with the agricultural calcite and what I used on the background.   I am not sure my painting style is a good match for that, so maybe I keep experimenting with a mix of stand and refined linseed.

More detail on the actual mixing and "grinding" process.

He is using a knife to grind, whereas my recent attempt used a muller.  Both seem to influence the texture of the paste.

https://www.wetcanvas.com/forums/topic/tad-spurgeon-s-quot-putty-medium-quot/

Brought me here

https://web.archive.org/web/20160315125433/http://www.tadspurgeon.com/puttymedium.php?page=puttymedium

Basic putty is made from a combination of oil and stone dust. In order to produce a stronger paint film, the oil used in the putty should be stronger than the raw oil of commercial paint. This can be painter-refined organic linseed oil, and/or a semi-heat bodied oil, and can include the addition of a small percentage of thicker oil such as sun oil. There are many variations possible within this deceptively simple recipe, these result in paint with different rheologies or types of behavior under the brush.

In response to the modern belief that resin, and therefore solvent, is necessary to achieve the effects of the great masters...

Enter the modern conservator, armed with gas chromatography, mass spectrometry, and a host of allied high-tech paint film analysis techniques which enable the detailed analysis of minute samples. In Technical Bulletin #15, (1994) London's National Gallery published an extensive article titled "Rembrandt and his Circle: Seventeenth-Century Dutch Paint Media Re-examined." The conclusion was that, while some of Rembrandt's pupils used amber varnish in isolated cases, Rembrandt himself did not. With the exception of the occasional glaze using resin, Rembrandt's paintings were made with linseed oil. The most common additions were chalk and egg. This same group of conservators and scientists, writing in the Rembrandt volume of their superb Art in the Making series, makes the same case with more paintings in more detail. This conclusion proved so controversial with Rembrandt scholars that in the updated edition of the book in 2006, the authors go out of their way to point out that they can and do find resin, it's just not in Rembrandt's paintings. The same has been true of Van Eyck research: the medium was linseed oil. The same has been true of Vermeer research, linseed oil with protein, probably egg, possibly a hide size like rabbit skin glue.

Starting recipes,  although they do seem a bit more complex than I was expecting.

NB. BPO #5 refers to the part where he talks about Burnt Plate Oil.

Chalk Putty

      1 cup chalk
      2T 72 hour walnut oil
      4T 48 hour walnut oil
      2T Allback boiled linseed oil
      1t sun oil

      A nice combination of oils for general work, good boing, dries well. Chalk putties absorb more oil but also will break if stored. This is not an issue in practice, comes back together by simple mixing.


      Marble Dust Putty with BPO

      1 cup Marble Dust
      1t BPO #5
      1T sun oil
      3T+1t 72 hour walnut oil

      A little loose, a little gluey, dries with an increase in depth from the BPO.


      Smidge of Egg Putty

      1 cup Marble Dust
      4T 72 hour walnut oil
      1T sun oil
      1t BPO#5
      1t whole egg

      More set from even this amount of egg, tight detail, clean line. More egg would cause more seizure, the need for more oil to make it move. This type of putty can get a little rococo in practice, fun outside or for loose work. Can be tubed without going bad.


      Prehensile Putty Underpainting

      Make a dense putty with some thicker oil such as boiled or sun oil, add a small amount of a chosen color, perhaps raw sienna. Put this thinly and evenly on a panel with a large knife, carve into it to draw. Very layerable surface results. Can also be thinned with a little solvent for more control.

And my favourite bit.

The first time I worked with an oil and marble dust putty in a painting I realized that it was all possible. After six years in the labyrinth of older painting technique, a large, economy size Philip Guston light bulb went on over my head. Eureka, this is it. Many mixtures, a year of trial and error later followed: once again, simplicity proved inherently complex. What follows is a description of this technology in action. It flies, quacks, swims, has feathers, webbed feet and a bill. Is it, then, a duck? This is thankfully not for the uneducated craftsman to say. Hopefully, in the best 17th Century tradition, you will simply let your own experience with the materials be your guide. This is the essence of Rembrandt's advice to Van Hoogstraten: the authentic craft develops naturally from one's own experience. So, it seems reasonable to suggest that the search should not be for the lost secrets, but for one's own practice. This is in fact easy, you start making things. At first they might not be perfect, but the information here should provide you with a running start. And, if you are cut out for this the learning curve will not be daunting, because you will realize that you are finally headed in the right direction: towards the living craft.

So many useful details.   He deep dives into ingredients,  recipes,  etc.  
So lucky to have found this.  Thank you wayback machine.

He also mentions karma as a possible source.  Looks like they are in canada
https://www.kamapigment.com/home?___store=en

https://web.archive.org/web/20160314011752/http://www.tadspurgeon.com/the_book.php?page=the+book

Looks like the perfect book for learning more about calcite based mediums.

Now to find out if I can buy it within my budget.   Or if it can be bought at all.  Sigh.

At least the wayback machine loves me

I'm nearing the end of the tube I made before.  It wasn't that much medium, but it worked really well to stiffen soft paint and lengthen stiff paint.  It's also speeding up drying quite a bit.  Because of the stand oil (I think), the dry paint isn't as matt as many of the colours would be (not sinking in).

I'm thinking about exploring different recipes for the future.

Underpainting wants to be matt and quick drying, so perhaps a mix of the calcite and alkide walnut oil alone.

Regular layers do well with this calcite/valazquez style.  

Wondering if there would be a better option for glazing.  To extend already transparent pigments so they glow more and level out the brush strokes.  Maybe a soft mixture of calcite and stand?

Anyway, I made another batch following the description I gave above.  Put it in the tube and then saw how little of the tube it filled up so I made a second batch and put that in the tube too.  

Observations: this is a very 'long' or 'ropy' medium.  When I dab the palette knife in the paint and lift it, I can get several inches of 'string'.  It's a bit hard to explain, but this video shows the results (about 4:40 in case it doesn't auto-play to that location.


https://youtu.be/hT8zSSHVNi8=280

And watching that video again, I see I could put a lot more calcite in my medium.  Their valazquez is way stiffer than mine.  But I don't think I could mull the medium if it was that thick.  This might not be a bad thing as mulling is hard.  

Another thing to note is that my homemade calcite medium kept well in the tube so far.  No separation or change of characteristics.  

r ranson wrote:https://web.archive.org/web/20160314011752/http://www.tadspurgeon.com/the_book.php?page=the+book

Looks like the perfect book for learning more about calcite based mediums.

Now to find out if I can buy it within my budget.   Or if it can be bought at all.  Sigh.

At least the wayback machine loves me

Found it free pdf download  with permission of the author https://www.thomaskitts.com/page/36804/tad-spurgeons-book-living-craft

However, while it's been a long personal labor of love, Tad has decided to stop publishing hard copies and has converted it to a pdf you may now download for free. All 566 pages of it. Which makes this an incredible gift to you. (As a pdf, you can search the entire text as needed.)

...
I post this with Tad's permission since he will be taking down the website currently hosting it at the end of October, 2023.

...

The recipes for various calcite putties and why we use them start on page 331

Finding a physical copy seems impossible.   But I don't know if the local print shop would let me print a copy of the pdf and have it bound.  That much reading on a screen is going to be difficult.

Today I read that calcium carbonate is a common supply for pottery making.

They didn't elaborate on what they use it for in pottery, but suggested it works fine for these calcite putty mediums.

Gamblin Dry Pigments - whitening
seems to be made with calcium carbonate (PW18)
https://gamblincolors.com/oil-painting/color/dry-pigments/

Might be worth a shot if I can get it.