The "Open Period" Test: Walnut VS Linseed Oil as the Ultimate Painting Medium

[@Divertedflight]

With time the linseed paint layer will dry thoroughly in the under paint. The only risk noticed by some conservators is that when the paint gets to 1/8 to 1/4 inch thickness or greater. Depending on the pigments, some paint will never dry in the lower levels, but this seems unrelated to the types of oil used (though it has not yet been observed with walnut) Titanium white by itself and titanium white mixed with a slow drying colour seem especially vulnerable to this effect. Possibly because they're not only slow drying, but this paint being so opaque doesn't need to get very thick before it starts to block all sunlight effects to the lower layers.

[@zein9227]

Actually, there is a lot of inaccurate information in this video concerning the fatty acid chemistry of drying oils. Walnut oil is not superior to linseed oil in terms of polymerisation and film formation. The most important factor in film formation and its tensile strength and durability are unsaturated fatty acids which determine the amount of polymerisation, namely the α-Linolenic acid. The amount of unsaturated fatty acids that lend themselves to polymerisation are measured in iodine numbers. Everything above 130 is considered a "drying oil". Walnut oil has an iodine number of 130-160 whereas linseed oil is at 170-200. This number explains why linseed oil dries faster than walnut oil. There are more chains available to react with oxygen and this makes it considerably more stronger. By the way, many Old Masters used a type of purified linseed oil other than than those that are today commercailly availabe. The yellowing is caused by mucilage and other protein and saccharides from the plant and seeds. They used methods to reduce amount of mucilage considerably. The only real exception is Leonardo da Vinci who is known to have used walnut oil. Old Masters also used toxic lead compounds in their colours. Lead is a strong siccative and creates the most durable paint films with drying oils. Titanium White and it's behaviour in drying oils is quite the opposite of lead components.

[@MM-fb9fi]

Your info is dead on but only hints about a lot of good information. Also there is little need to have this dreaded fear of lead in paint. It is really only horribly toxic in California. In adults lead can cause neurological problems and the solution is wear gloves. Men working making batterys rarely test positive for lead due to excreting it in urine and sweat. Lead in children will replace the calcium in their bones and I seem to recall there was neuro damage as well. The reason for not using lead-based house paint is some children would gnaw on the windowsill and ingest the paint. I have often wondered just how many per year did just that.

[@kittydukakis]

Safflower oil dries just fine,. It dries slower than linseed but faster than poppy oil. Most white oil paints are now ground with safflower oil.

[@ethonica]

Yes. I believe the video was mistaken about that. Safflower is normally a drying oil. It’s just that it’s a slow drying oil. It’s also more runny, so it’s thinner than linseed oil.

[@MM-fb9fi]

Something that is missing in a conversation about safflower is how acid is it. A high acid ph is required in order to make a better bond. Never use poppy seed oil. I have seen no reference to poppy oil being used by the old masters.

[@josephtermeer5196]

Very informative. Thanks for the seeds, I need to develope my renaissance tree of knowledge.

[@lindabay1491]

I use a small amount of walnut oil for my medium and nothing else. I like that the colors seem to maintain their brightness without sinking or going flat. Do I still need to oil out my painting between the dried layers, or should I just skip this since my colors have remained vibrant?

[@zannek9342]

Dear artists, it's super interesting, I learn a lot , thank you for sharing and being so pasionated. I live and paint in France, and I often have problems with lighting my model or my still life. Do you have a video where you talk about lights and how to produce good shadows ? I'd love to hear about it from you ?

[@chrisgriffith1573]

I use linseed oil first, and then got into walnut/linseed oil mix, then walnut/stand oil, then walnut/safflower. I'm using linseed oil like an accelerant. I use more additives in the last layer- like glass or silica to make the surface glisten or whatever- more glaze- so I want less yellowing to happen in the future. Linseed oi has a tension to it- due to the fact that it develops a skin, and if you have a thicker layer of oil, this tension could build and be a factor in the future by the way the oil layer has tension. This is why it will crack and peel like a dry lakebed in a hundred years or so. That curling is the tension pulling from the top that dried faster.

[@ponchoking55]

walnut oil smels sooo good

[@rowanwills2334]

I just bought a bottle of walnut oil from Kremer here in Munich. It looks like the same one you have there "Walnussöl Raffiniert". But it also says on the bottle that a siccative must be added. Is this wrong, or do they just mean that without siccative it will take longer to dry than linseed oil? I also bought a small bottle of sun-thickened walnut oil. Very expensive stuff, hopefully it will be worth it!

[@MM-fb9fi]

Most use thinner for a Misbegotten idea it makes the thin layer they have been told to use in the starting of a picture. If you get the oil too thin the paint does not bond onto the canvas very well because there is a reduction in the number oil molecules. Better to understand a little chemistry here. Acrylic paint can be used as a "thin layer" on an acrylic primer. Just again, do not dilute it too thinly. Understand you are putting plastic paint onto a plastic primer. How ever acrylic will not adhere to oil paint but oil paint will adhere to plastic, if it is put down as the second layer and on top of the plastic. It is best to allow an acrylic underpainting to dry 2 days and then begin to apply your oil paint. Plastic does not go on top of oil.

[@kingyo9783]

Thank You,I didn' t know it!Can I clean brushes with linseed oil and paint with walnut oil as a medium in the same time?

[@stephenfularz7573]

That's what I use walnut oil as a medium and a brush cleaner.

[@pollyester6627]

Leonardo used walnut oil.

[@Divertedflight]

Safflower oil comes in two basic types. High oliec and high linoleic. The oliec is the non-drying variation and the linoleic is the semi-drying variation. Only the linoleic should be used by artists for brush storage or paint making. Personally I wouldn't recommend it as a paint medium. It would probably be wisest to buy this solely from an art store (which should naturally only sell linoleic.) as other suppliers linoleic could contain a non-drying additive to increase shelf life. Most safflower oils in supermarkets will be Oliec.

[@yibuseato]

Have you ever used Gamblin Solvent free gel? It contains safflower oil so I’m wondering if I should stop using it. 🤔

[@Divertedflight]

@@yibuseato No I haven't even heard of it, but I'm sure it's better than the safflower medium that Willem de Kooning made. That sometimes never dried even after decades on gallery walls. Possibly its semi-hydrogenated to gain a gel like quality. If it achieves the effect you're looking for then it's better you use it. Personally all I need is a little stand oil to aid flow, but your needs maybe different.

[@ethonica]

I feel this comment is misleading. *Safflower oil is a drying oil.* ​By default, safflower oil is a drying oil because safflower oil is naturally high linoleic. Modernly, they made a variant of safflower that is genetically modified to have higher oliec fatty acid for use in cooking. Thereby, safflower cooking oils are not suitable for painting. Ofcourse that means those kinds of safflower oil are normally sold in grocery stores. Make sure to also check the ingredient list that it contains pure safflower oil. Some add vitamin E as a preservative, that would make it a non-drying oil/not suitable for painting. However, it’s still safe to assume that most safflower oils are the normal high linoleic (drying oil, safe for painting) type, especially those sold in artist supply stores and suppliers of cosmetic manufacturers. @@yibuseato Gamblin solvent free gel is artist-grade and thereby safe to use for painting. Anything by Gamblin is safe for painting. Gamblin is a reputable brand that puts effort in researching their materials well.

[@neogerula]

what would be the result of mixing wallnut and linseed oil for the same pigment togehter ?

[@ethonica]

Like normal. Just that the parts with more walnut oil will dry slower and yellow less in the next 5 years.

[@neogerula]

Thank you , so iti s possible to mix different vegetal oils and maybe even vehetal with mineral oils( wich I think allmost do not dry) or with alkyd , resulting different properties of the mixtures given by the proportions... delightfull.@@ethonica

[@williamwinn948]

never tried walnut oil

[@queenvashtiful]

What is a good alternative to walnut oil if you are deathly allergic to walnuts?

[@zein9227]

Artist Grade Safflower oil or Poppy oil (which are semi-drying). You can also used highly purified linseed oil add a few drops of a slow drying or semi-drying oil into your colour if you want the open time of walnut oil, e.g. grape seed oil, refined high-linoleic sunflower oil or oil of cloves which will keep your paints open for a very, very long time (up to several weeks). Don't ever use walnut oil if you're allergic. It's fumes will harm you severely if not lethally because of your allergy.

[@yibuseato]

This may be a dumb question- I use a medium that contains safflower oil (Gamblin solvent free gel) is this a bad idea? Have you any experience with this product? Thanks so much for your wonderful videos ☮️💟

[@ethonica]

Gamblin Solvent Free Gel is fine to use. Safflower oil is a drying oil. The statement in the video about safflower oil not drying is misleading. Maybe he bought his safflower oil from rhe grocery store and got the cooking oil variant. Safflower oil dries just fine. It just dries slower. Safflower is also less yellowing than both walnut oil and linseed oil. Safflower is also thinner, more runny, which makes it better choice for cleaning brushes without solvent. Gamblin solvent free gel however, is more alkyd-based than safflower oil. That’s why it’s in a gel like consistency.

[@chrisgriffith1573]

I have thought this for a long time, (the part about keeping the brush in safflower oil) you definately don't want that in your mix after... which only means you are back to washing out the oil... redundancy?

[@ethonica]

I believe the video was misleading about that. Safflower is normally a drying oil. It dries just fine. It’s just that it’s a slow drying oil, so it might make your paint dry a bit slower. It’s also more runny, so it’s thinner than linseed oil which makes it better to clean your brushes with.

[@paulashford4155]

Well it is good to know it is an option. I am not technical and probably not qualified to say much on the subject. In the paint samples section of my Rembrandt books, they say he mostly always used linseed oil, and occasionally used the other oils. So I will stick to linseed, myself.

[@ashtonburgess9569]

Walnut oil doesn't yellow over time with white paint vs linseed ... Says Google AI

[@rangerknow940]

This is nonsense. There is no such thing as, "the ultimate painting medium". The best medium for what exactly? They all have pros and cons and that's the beauty of oil. Keep in mind that the oldest oil painting ever found was done using poppy seed oil.

[@ethonica]

I agree that there is no ulimate painting medium in oil paint. But to call it all nonsense is completely false. They did not say walnut oil is the “ultimate painting medium”. He was just enumerating the benefits of walnut oil and why he prefers it. His fault may be that he did not include the disadvantages of walnut oil, like being slower to dry that linseed oil.

[@BananaInDaHouse]

Alot of misinformation and incorrect statements in this video unfortunately