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(brian baade)
Hi, This is a multipart question so it will be
easier for me to answer the separate sub-questions within the body of your text
(in red)
Hello! I have a few questions regarding oil mediums.
1. I have done some of my paintings with oil medium that has Venetian
turpentine in it. The formulation of this medium is one part of stand oil,
one part of Venetian turpentine (Schmincke Natural balsam/larch
turpentine) and two parts of turpentine ( Lefranc & Bourgeois
rectified turpentine) . I have read that Venetian Turp/Balsam is not that
recommended, but at the time i didnt know, so i did some very important
paintings with this medium. What are your thoughts about this medium? I was
very carefull about layers ( fat over lean) Do you think that these paintings
will be ok, even if i did them with this medium?
Venetian turpentine is a natural balsam, meaning
that it is a soft resin that still contains the essential oil. Like all soft
resins, the resinous component will remain sensitive to solvents. Oil paints
containing soft resins will also be more sensitive to solvents. If these works
are varnished and the varnish ever needs to be replaced the oil paint could be
damaged in the process. If the work remains unvarnished this is less likely to
be a problem although that will cause lead to other issues and my not be the
aesthic that you are looking for. If the work is varnished the possibility of a
problem will be direct proportion to the amount of medium that was added to the
paint. Small amounts are unlikely to have a major effect, larger amounts are
much more likely to cause problems if the painting is ever cleaned. Fat over
lean refers to the idea that subsequent paint layers should be more flexible
than those below them. This would have no impact on the solubility of paint
layers other than the likelihood that your last paint layers are likely more
sensitive to solvents than your first.
2. I was also using Winsor and Newton Liquin Original medium.
What are your thoughts about this medium, do you think this is good archival
medium to use?
Alkyd mediums like Liquin are stable and when added
to paint do not increase its sensitivity to solvents. Whether they move and
handle in a manner that is pleasing to you is a separate issue. I do worry
about people loading their paint with excessive amounts of alkyd mediums
because they believe that they are not deleterious. Alkyd mediums do yellow,
like almost every organic material. Excessive additions of alkyd will result in
a paint film that will amber slightly over time.
And is it really true that you dont have to be that careful about
"fat over lean" rule with W&N Liquin original? I always try to be
careful about layers even with this medium.
I have never heard this and do not agree. Recent
studies have shown that alkyd paints are slightly less flexible than oil paints
containing the same pigments/etc. While the addition of medium to an oil paint
is not exactly the same as an artists alkyd paint, there are similarities that
suggest to me that this concept is flawed. I am not trying to contradict myself
here, I do believe that alkyd mediums are stable, just not that their use
allows the artist to ignore sensible working methods.
I wanted to ask is there some substance that can be added to Liquin as a
thinner, some solvent, because i paint in several layers? Or i should just
use less Liquin medium in first layer and then add medium as i build up the
painting?
I find that when people use straight alkyd
throughout their painting it is very easy for the painting to become excessively
greasy if there are many layers all containing neat medium. Of course, each
artists working method will be different but it seem to me that it would be
sensible to use no medium on the first layer or so, a bit of medium thinned with
a solvent (like mineral spirits) and straight medium added to the paint only for the final layer(s).
Also i have combined two Liquin mediums on one painting.
I used Liquin original for first layers and then used Liquin Fine Detail for
finishing layer. I have contacted W&N about this and they have told me that
is totally ok to combine those two mediums, i just have to keep in mind
"fat over lean" rule when i am combining them? What are your thought
about this?
This sounds reasonable and correct.
3. In museums there are some paintings that stood the test of time, and
these artists did scumbling techniques, and glazes, and it really seems that
they sometimes didnt care that much about "fat over lean" rule, and
still it looks great. Do you think that we should maybe try to some extent
to apply these rules, but not to be very precise and that concerned about
it?
To be honest, I know of no documented use of the
term “fat over lean” or even an allusion to a similar concept before the 19th
century. It is likely that it was just natural to construct a painting in the
manner that roughly follows a similar procedure. Dryish paint does not adhere
well to greasy paint. Glazes tend to work best as the final couple of layers.
Scumbles were certainly used but these can be applied lean through physical
manipulation and by the addition of additional medium. Follow sensible
technique but do not be so imprisoned by them that you are unable to make the
artwork that you want to express.
4. And i wanted to ask what types of oil mediums were least changed through
time, and prooved to conservators/restorators as most stable?
Generally, mediums that contain only oil and solvent
or at least, those that do not contain a soft resin are the most stable. Soft natural
resins promote solubility, yellowing, and brittleness. Hard natural resins
promote brittleness and yellowing but at least they do not promote solvent
sensitivity. This is practically moot as there are no readily available hard
resin mediums (outside of the boutique materials, cottage industry art
materials market). Oil only promotes yellowing and only if used in excessive
amounts.
Alkyd mediums are a good middle ground as they create
a paint film that is resilient like an oil only medium but contributes the
gloss.and refractive index of a medium containing resins (to be clear, the alky
is an oil modified synthetic resin).
I have heard that these were the ones which were more basic (stand oil +
turpentine, or white spirit, or something like that).
What are your advices about medium choice and what is
the best way to paint in layers?
Simple formulations and layering systems are
generally better than complex ones. Work in only as many layers as is necessary
to create your intended aesthetic effect. Do not overload you paint film with
mediums and reserve their use for special effects and for later paint layers.
Follow some sort of system where you mostly apply nmore flexible layers over
more rigid ones. You can do this with judicious additions of a stand
oil/solvent medium or using an alkyd medium. For some paint effects, you can do
this without adding any medium.
Thank you for time and efforts!
I hope this was of some help.
All the best!
Marko Karadjinovic