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View Full Version : What's in a typical oil ground?


Quality
02-18-2019, 09:34 PM
Can it be made at home? Looked for a recipe, but came up empty. Any info on this?

Much appreciated

bokaba
02-19-2019, 01:14 AM
You probably could make your own. Titanium white + linseed oil and something for texture like crushed marble or chalk perhaps. This appears to be what most are made out of.

RomanB
02-19-2019, 01:51 AM
Stretch your canvas. Size it with glue very lightly using a wide brush, a little chalk could be added into the glue and stirred well before application. Let sized canvas dry overnight. Mix well Lead White with 1/4 of chalk by weight, mix them with bodied linseed oil, gently applying oil drop by drop and mixing the paste with a painting knife to avoid adding too much since this ground is very lean. Then grind on a glass or marble slab using a glass or stone muller, 100 grinding movements is enough to get very fine result. Apply your ground to the canvas using a stiff wide brush brush or a slightly curved knife if you want to have less pronounced texture - in this case tops of threads will become visible through the ground. Let it dry for a week or two. Use it soon after making, old oil grounds have bad qualities.

DebWDC
02-19-2019, 10:32 AM
Hi Quality –
There is no typical oil ground :) thanks to modern manufacturers and marketing.

Almost anything can be made at home. Some things are not worth doing at home if one can buy them easily and inexpensively. Also, the devil is always in the details. The details to consider are the specific use or application, safety, cost, convenience, and willingness. The answers one gets here on Wetcanvas will be based on personal experience, information from conservation sites, information from manufacturers, and “common wisdom”. It is the common wisdom which is difficult to evaluate effectively because it is composed of actual facts, misinterpretation of facts, belief, and a cultural assumption that traditional or great master techniques will always work or are always best.

The most appropriate ground will be different for canvas stretched on canvas bars than it will be for a panel or canvas glued to a panel. This is based on the different materials and their physical properties.

My personal experience:
I have personal experience applying to stretched canvas first rabbit skin glue, then traditional gesso made with lead white paint, ground chalk, and linseed oil. It applied easily, but within 2 months, with very careful handling and as I started to paint on it (meaning I put a little pressure on the canvas with my paint-loaded brush), it cracked. I prepped several canvases this way, and they all cracked. The cracks were over the entire surface of the canvas, but mostly several inches away from the edges by the stretcher bars; they were evenly distributed across the surface, they were all joined together so that that the uncracked canvas pieces were small (less than 5 centimeters in any direction) and uniformly lozenge or diamond shaped, following the weave of the canvas.

Why did I prep the canvas this way? Because my ill-informed university painting teacher, who painted in acrylics, told me to do it this way, as he had read this is the way the great masters had done it. Well, he was wrong. My previous painting instructor, from a different school, had taught me to never use chalk-based gesso on canvas, as it would be too brittle and crack. I was too embarrassed to ever tell my previous teacher what I did, as he was a great stickler for proper technique and materials.

The reason why they all cracked is that stretched canvas flexes, and gesso made with chalk (or marble or calcium or any other similar substance) does not. So, the gesso will crack when the inflexible surface on the flexible canvas is stressed through physical pressure or through humidity changes. Rabbit skin glue and both cotton and linen canvas are all hygroscopic. Humidity changes constantly, even in well-controlled environments like art museums. Just imagine what your house experiences :) 

Chalk-based gesso is appropriate for prepping inflexible panels, and has been used for this by many painters for centuries, and is still used this way by traditional eastern orthodox icon painters (my sources being art history classes taken 40 years ago and more recently talking to the owner of the Rublev oil paint manufacturer). I have a vague memory that Andrew Wyeth did something similar for his gouache paintings.

Safety considerations:
The recipe given by RomanB contains, if I am interpreting this correctly, dry lead dust and not lead paint. If you choose to do this, then take the necessary safety precautions: OSHA particle mask, a contained area to grind the mixture, very careful clean up, etc. I personally find heavy-metal dust to be too scary to work with, so I don’t ever do it.

A few quick sources for more information:
http://www.wetcanvas.com/forums/archive/index.php/t-1384543.html
http://www.wetcanvas.com/forums/showthread.php?t=1351324
https://gamblincolors.com/video-demonstrations/

My suggestions on prepping stretched canvas (even though I now only use panels and purpose-made paper):
Sizing: seal the canvas surface with a non-hygroscopic substance, such as PVA glue.
Ground or priming: Thinned oil paint of almost any color (not umber) will suffice. I think many people use lead white because the color is traditional and because the lead makes a good chemical base for subsequent colors (quickens drying and increases adherence of the following paint layers). Zinc white is problematic, as there is conservation research showing it causes problems a few years after the painting is complete. Acrylic ground made for oil painting will probably work just fine, but I have no experience with it. I use thinned white lead oil paint only when the panel surface is brown. If the surface is already white, then I don't put on a ground. Let your reasons for wanting to apply a ground be your guide.

My suggestions for prepping panels:
Sealing: use PVA glue on all six sides of the panel.
Ground or priming: same as above.

Please let us know how it turns out.
Deb

contumacious
02-19-2019, 11:45 AM
Some excellent information and advice from Deb. I too avoid using animal skin sizing or grounds unless I really need to such as with egg tempera and then only on rigid supports such as directly on panels or canvas mounted to a panel.

As for making a lead ground, it isn't much different than making your own oil paints other than you should add something to give it more tooth and if desired more absorbency than regular oil paint. As long as your mixture has a drying oil in it such as Linseed, pigment of your choice such as Titanium White, Lead White and / or some non white pigments if desired, some thing for tooth such as silica, calcium carbonate / whiting which can be manufactured or naturally occurring such as chalk or marble dust and to speed drying some alkyd resin. My reading indicates that if you are OK with using it and know how to handle it safely, adding some lead pigment to your ground is considered beneficial for faster drying and a stronger film. I always add lead to my grounds.

You can make it totally from scratch or take white oil paint and add the calcium carbonate to it. Depending on how thick you want the consistency, vary the ratio of oil to solids. Using thicker oil products can also help you moderate consistency.

Again, echoing what Deb posted, I choose to avoid animal hyde products if I can so I use either PVA, Acrylic Gesso or Acrylic Medium to size canvas. Personally I don't like PVA so I use acrylics. On bare panels, you don't need sizing with oil grounds but on wood a primer isn't a bad idea. I like to put a priming coat on first with XIM UMA Bonder Primer for superior adhesion of the ground to the panel, but there are other excellent primers you can use for your first coat, or you can apply the oil ground directly to the panel.

This page gives a recipe that could be a decent starting point other than the recommendation of using hyde glues.

http://www.cad-red.com/mt/o_o_cnvs.html

Richard P
02-19-2019, 12:11 PM
I agree, excellent post Debs!

I use Clear Gesso which I believe is basically an acrylic medium with silicia for tooth and stiffness. It's non-absorbant (or very little) and I use it on panels for a nice toothy surface.

spero
02-19-2019, 02:45 PM
Ground or priming: Thinned oil paint of almost any color (not umber) will suffice.

Why isn't umber a good choice?

DebWDC
02-19-2019, 05:50 PM
My understanding is that pigments for paint which contain metals (lead, zinc, manganese, cobalt, iron, maybe antimony) interact chemically with the oil (linseed, walnut, safflower, poppy, etc.) and speed up the oxidation and therefore the drying rate. Some speed it up too much, some speed it up hardly at all, and some just right – just like Goldilocks and the porridge.

Many browns, like umber, usually have manganese and iron in them. In large enough quantities, that can cause your paint layer to dry too fast and crack and may affect subsequent layers as well. Google Japanese dryer or cobalt drier. Maybe it will be ok, but I want to control technical problems without too much thought, and save my brain cells for the hard work: composition, values, edges, not breaking my glass palette AGAIN… Lead, on the other hand, speeds up drying just a little bit and helps with subsequent paint layers, which is one reason it is so popular as an oil paint ground.

This is a great website! I donate $20/year because I use it regularly.
http://www.artiscreation.com/brown.html#ci_pigment_brown

I hope other people weigh in on this, because I am not a chemist or expert.

chamisa
02-20-2019, 07:57 AM
If all you are after is a less absorbent already gessoed canvas or panel, can you just put on a thin layer of Liquin which dried quickly?

spero
02-20-2019, 08:36 AM
I was familiar with umber's drying time, and didn't know if there was another property I was blind to. I didn't know it was because of a chemical reaction between the metals and the oil, so thanks for that! It seems like a faster drying ground would be okay, at least as far as fat over lean is concerned. But I'm also no chemist, so I don't know the overall implications of using umber as a ground.

contumacious
02-20-2019, 09:52 AM
If all you are after is a less absorbent already gessoed canvas or panel, can you just put on a thin layer of Liquin which dried quickly?

Alkyd mediums and even just plain linseed oil will reduce the absorbency of absorbent grounds. You don't have to wait for them to dry unless you want to for whatever reason. Basically if you don't let it dry, you are painting into a couch but with nothing underneath it besides the ground. Most alkyd mediums and even oils can dry fairly slippery, so test before you use them this way to see how much you prefer. I had some very absorbent panels, not by choice, on a road trip once and brushed on linseed oil until they soaked up enough to not be paint vacuums. That was all I had with me to fix them. It worked fine and still held the strokes well, just didn't suck them dry. They were dry to the touch the next day.