Upload new images. The image library for this site will open in a new window.
Upload new documents. The document library for this site will open in a new window.
Show web part zones on the page. Web parts can be added to display dynamic content such as calendars or photo galleries.
Choose between different arrangements of page sections. Page layouts can be changed even after content has been added.
Open the Navigation Management window, which can be used to view the full current branch of the menu tree, and edit it.
Move this whole section down, swapping places with the section below it.
Check for and fix problems in the body text. Text pasted in from other sources may contain malformed HTML which the code cleaner will remove.
Accordion feature turned off, click to turn on.
Accordion featurd turned on, click to turn off.
Change the way the image is cropped for this page layout.
Cycle through size options for this image or video.
Align the media panel to the right/left in this section.
Open the image pane in this body section. Click in the image pane to select an image from the image library.
Open the video pane in this body section. Click in the video pane to embed a video. Click ? for step-by-step instructions.
Remove the image from the media panel. This does not delete the image from the library.
Remove the video from the media panel.
On various art forums people often ask about using grocery store cooking/salad oils, such as walnut oil, as a painting medium. They are usually trying to save a bit of money. It seems like a false economy that could likely cause probelms down the road and negate hours of work put into the paitning process just to save a few dollars on materials. I'm aware that there is an obvious problem with some grocery store oils containing added anti-oxidents to maintain freshness. Are there other issues, related to the differences in how edible oils are processed as opposed artist grade oils, that can cause problems in the quaity of paint film formed?
Move this whole section up, swapping places with the section above it.
Certainly flax and walnut oils of a high quality can be purchased from
sources intended for consumption. As you state, these may have been modified or
even processed in such a manner as to make them undesirable for drying oils
intended for paint binders. Tiny additions of rape seed oil or other seed may
have no effect on the quality of a salad dressing but could have disastrous
results in a paint binder. Additionally natural or GMO modifications of fatty
acid ratios could be very beneficial for health benefits but be problematic for
I have, however, conversed with individuals who have found high quality,
cold pressed drying oils in health food stores. One would need to test any
sample for its drying rate and compare that to samples intended for use by
artists. At least you could rest assured that the speed of oxidation of a
health food store oil would be completely inherent and not a result of a heavy
metal catalytic siccative.
On the other hand, all of this assumes that cold pressed oils are inherently
superior to commercially available, and generally very affordable, alkali
refined artists oils. There is no evidence to support this claim.
It's my understanding that, as Brian points out, edible flax oil can be derived from modern hybrids with fatty acid ratio optimized for digestibility. Some edible oils have a "foot" of mucilage and other impurities that should not be introduced into paint. Da Vinci's instructions for extracting and clarifying oil from walnut meats makes me think that he might not have considered raw pressed oil sufficiently clean for use in painting.
I think the modifications go beyond digestibility, The primary difference in the fatty acid profiles of seed oils meant for consumption versus paints is lessening the linolenic and linoleic acids as much as possible while increasing the oleic component, which is non-drying. This limits oxidization, which is perceived by the consumer as an oil going rancid, which is obviously undesirable. So even if the oil does not purport to have an anti-oxidant added, simply the type of fatty acid profile can dramatically impact its ability to form a film. The food industry is huge - even in terms of natural foods - and so a lot of resources are used to maximized strains of safflower and flax for different purposes. I would also note that recent conservation cases of liquefying paint points to oils being used that were dangerously on the edge of being non-drying oils and so it is critical to only use oil stock where linoleic and linolenic acids are maximized - which is the opposite of what is desirable in a food-grade product.On walnut oil, I think the main difference might be that - as far as I know - different strains of walnut trees have not been created for different industries and so the oil sold in health food stores and the one used for paint might be essentially coming from the same or very similar sources. Finally, as has been suggested, any oil you use from a store would at minimum need to be tested to make sure it dried in a reasonable amount of time.
I one had my hands on a DeKooning where he used salid oil as a medium, it was still wet 30 years later.