I recently did a little research for a customer question and thought I would share it.
Which watermixable oil colour dries faster Winsor & Newton Artisan or Royal Talens Cobra?
Cobra is faster drying overall and all the colours dry in the same amount of time. Cobra contains added driers to make all the colours dry at the same rate. Artisan does not have added driers and this means each colour dries at a different rate, some pigments are fast drying and some are slow drying. Driers are usually only added to student-grade colours but Cobra is an artist-grade colour, so it is a bit unusual.
Cobra oil colour has a uniform drying time and degree of gloss. Depending on the thickness of the layer, it will be dry to the touch in 3-5 days. This is much quicker than traditional oil colours.
Information on the Cobra website.
Winsor Artisan has the same drying time as Winsor’s Artist Oil Colour and their student colour Winton. After the water has evaporated it is the same as their regular oil colour.
As with traditional oil colour, Artisan colours have different drying rates.
Here is a list of the drying rates of pigments on the Winsor & Newton website.
Fast drying – around 2 days
Prussian Blue, Umbers.
Medium Drying – around 5 days
Cadmium Hues, Phthalo Blue (red shade) and Phthalo Greens, Siennas, French Ultramarine, Synthetic Iron Oxides, Ochres, Titanium White, Zinc White, Lamp Black, Ivory Black.
Slow drying – more than 5 days
Cadmiums, Permanent Rose (Quinacridone), Permanent Alizarin Crimson.
Does a hair dryer help to speed up drying time? Have
to ship a portrait tomorrow!
Hi Luz
I hate that panic!
But im afraid there’s not much you can do. A hair dryer might help at the beginning in the first day or two to remove the water by evaporation. But all the weeks after that the painting is drying as all oil paintings do, by slowly absorbing oxygen from the air.
I dont know your situation, but all selling artists have been in a similar situation.
A client doesn’t know how long it takes to dry, they only know the painting is finished and want it.
If they need it for a special occasion they get stressed – you need to be the voice of reason. Prepare them in advance and give yourself a few extra weeks.
If you ship it wet or unvarnished it is likely to get damaged. Perhaps they can settle for a print out of a photo of the painting, if the deadline is because they wish to present it to someone.
If it is for a competition, they often disqualify tacky paintings ehen they unwrap them, they want well-dried paintings.
I’m sorry to say the best thing to do is learn for next time as all artists have had to do. (I’ve sat up all night with a painting on a radiator and trying repeated spraying with retouch varnish, it doesn’t work.)
If you know you have a short time use Fast Drying Medium or a brand that dries quicker. The brands are different for each artist depending on how you paint – thick/thin, water/medium, etc. Speeding drying of oil paintings doesn’t work and may lead to structural weaknesses, so they contact you in a few year to say its cracked.
I’m sorry I couldnt be of more help than to give sympathy!
Hi Liz,
Is it possible to use the cobra medium to
thin the paint out and apply a very thin
initial layer – wait for it to dry and then
work on top with paint from the tube to
form a thicker layer? Thank you!
My water mixable oils dried with gloss.. this has never
happened before except when I’ve used black… it was
brown…(burnt umber). Is this because of the color
used or the application of paint? Thanks
Hi Edwin,
Thanks for your comment. It sounds like there may have been a lot of the binder in the paint that you were working with. If a tube of paint has been stored vertically for a long time (possibly prior to you buying it) the pigment can settle in the tube. This means that when you squeeze out some paint the binder:pigment ratio is uneven and more oil comes out, and this makes the surface gloss even when dry. It could be worth massaging the tube while the lid is still on to try and re-disperse the pigment, or give the contents of the tube a stir using a straightened paper clip. If the results are still not quite you were expecting do get in touch with us by emailing customerservices@jacksonsart.co.uk
Best wishes
Lisa
Hi
Have I ruined a painting done by artisan oils by coating it
with artisan painting medium , Willie remain sticky to
touch
Hi Gary
In this test I found the Artisan mediums stayed sticky for a few weeks. The Holbein mediums did not.
https://www.jacksonsart.com/blog/2013/05/09/water-mixable-oils-compared/
I like the Artisan paints but not their mediums. They smell strong and stay sticky.
I would recommend Holbein or Cobra mediums.
You could try removing the top coating with a cloth and turpentine, but it could damage your painting. Or you could use it as a test case and leave it in order to see if it ever dries. My tests were only a few weeks so I don’t know if my sticky Artisan mediums eventually dried. Please let me know if you find it does.
Why is my canvas still stick after 2 weeks. I painted with water soluble oils.
Hi Shirley
I will do some tests and get back to you.
Can I ask a couple of questions:
What brand did you use?
Did you use water or a water-soluble medium to thin your paints?
What did you paint on?
Are all the colours still sticky or just some, and which ones are they?
Hi again Shirley
I did some extensive testing of water-soluble oils recently and will publish a blog article about it tomorrow.
I found that the brands that dry shiny are the ones that stay the most tacky after they are dry.
I always recommend that a dried oil painting be varnished for protection and to give a consistent finish to the surface sheen. All varnishes will cover the tackiness you are experiencing. But you will need to wait until the oil painting is fully dry, usually at least 6 months. In the meantime a retouching varnish will also cover the tackiness and can be applied as soon as the painting is touch-dry.
I can help you more if you could answer a few questions:
What brand did you use?
Did you use water or a water-soluble medium to thin your paints?
What did you paint on?
Are all the colours still sticky or just some, and which ones are they?
Hi,
I have just finished a painting using
Winsor and Newton warermixable oils
but the black is Georgian. Whilst the
rest of the painting is dry the black is
still sticky after a week. What can I put
over it? Thanks
Hi Debbie
The stickiness doesn’t mean that it is still wet.
I did some tests recently and found that Georgian stays tacky even after it is dry.
When the painting is fully dry (in 6 months or so) you can put a picture varnish on and that will make the whole painting hard and smooth, covering the tackiness.
In the meantime, you could spray on a retouching varnish to cover the tackiness until you get to varnish it.
You might want to read this more recent article.
Water-Mixable Oils: Vibrant Colours, Easy-Cleanup and They Needn’t be Sticky
What is a picture varnish?
Hi Debra
Picture varnish is the name for the final varnish of an oil painting.
You have fantastic blog posts on painting
tools and materials! Thank you for
providing this resource. I am in the USA,
so I am not sure ordering is feasible with
shipping costs and flammable materials,
but I will see.
Hello.
I’m glad you find the information on the blog so helpful! That’s great to hear.
Yes, there are many items that we can’t ship by air as they are hazardous and heavy items are more expensive to ship. But lightweight items like watercolours or pastels aren’t too bad and we have a deal on shipping brushes that you might be interested in. Free shipping to the US and Canada for brush-only orders over £30 GBP (about $45 USD, at the moment).
Hi,
I used Artisan oil paints which I diluted
with water and Artisan linseed oil, the
paintings seemed to dry as normal, but
now (nearly a year later) some of them
started to form a wet, seeping surface,
the ones hanging upright are literally
melting down the canvas. It’s seems like
the areas where the layers are thicker (no
impasto, just several thin glazing layers)
are forming a tacky , tar like sticky puddle.
I don’t understand what went wrong, I
used the same paints and medium for
other paintings and they seem fine, so far
anyway.
That doesn’t sound good. I have not seen that before. I have emailed Winsor & Newton and asked what they think. I’ll get back to you with their reply when they respond.
Hello, I have just sprayed 2 acrylic
commissions with Royal talens satin
varnish, 24 hours later they are still tacky
and I need to post them! Bit of a panic
going on! Never had this trouble with
Winsor & Newton spray varnish. Will they
dry??? thank you.
Hi Jayne
I’ll need to ask a couple of questions to try to figure this out.
Which Royal Talens varnish is it?
It looks like we only do the satin in the Cobra varnish, is it that?
How dry and thick was your acrylic painting?
Thanks
My apologies, I didnt see your reply, I
thought it may give me an email
response/alert.
Yes it was the satin, purchased from
you, and it did eventually dry, I
popped them near a radiator but it
did take a few days. panic over!
However, if you could let me know
how long it takes for the water
soluble oil paints to dry enough to
varnish, that would be a great help,
thank you.
Hi Jayne
Yes, I thought it sent you a response when we replied, it does for some people. Perhaps you have to tick a box to be notified?
Your first question was about spraying the Cobra varnish on acrylics. This one is about spraying it on WMOs.
Using oil varnish on acrylics is fine, they cause no problems. I’m not sure why it was slow to dry. Very thick layers of acrylic, especially if you use lots of gel or acrylic mediums, can take a few days to dry through to the centre and that water evaporating could have cause the varnish to dry more slowly.
After the water has evaporated in the first few hours, water-mixable oils dry just like conventional oil paint. So you need to wait up to 6 months for them to be dry to the centre before you varnish. If you can’t wait until it is fully dry you could spray on a retouching varnish to give partial protection and still let the painting breathe to finish drying. The painting needs to be touch dry or longer and then you can apply the retouching varnish. You can have the collector live with the painting with just the retouch varnish or you can tell them to bring it to you in 6 months for a final varnish. A final varnish would just go right on top of the retouching. Remember to clean the dust off the surface before you do the the final varnish.
I have written a more recent article you might find interesting.
Water-Mixable Oils: Vibrant Colours, Easy-Cleanup and They Needn’t be Sticky
Hi Julie,
I’m working on an piece at the moment
using artisan watermixable oil paints. I’m
worried about the time it takes to dry as
the customer wants the piece in a couple
of months (less than the recommended 6
months drying time to varnish). Is
varnishing essential? Do you have any tips
for this?
Thank you
Tom
Hi Tom
I did some tests recently and found that many of the watermixable oils stay tacky even after they are dry.
Applying a picture varnish will make the whole painting hard and smooth, covering the tackiness.
If you can’t wait until it is fully dry you could spray on a retouching varnish to cover the tackiness, give partial protection and still let the painting breathe to finish drying. The painting needs to be touch dry or longer and then you can apply the retouching varnish. Remember that after the first few hours when any water has evaporated then you should treat WMOs the same as conventional oils. (My personal favourite retouching varnish is the LeFranc.) You can have the collector live with the painting with just the retouch varnish or you can tell them to bring it to you in 6 months for a final varnish. A final varnish would just go right on top of the retouching. Remember to clean the dust off the surface before you do the the final varnish.
I have written a more recent article you might find interesting.
Water-Mixable Oils: Vibrant Colours, Easy-Cleanup and They Needn’t be Sticky
Hi Julie,
I’ve been using water mixable oil paints
for quite some time now and I’ve always
waited a couple of weeks after they are
touch dry to varnish them with W&N
gloss varnish from their water mixable
oil range. But upon reading your article it
seems I should be waiting 6 months! Do
you know if W&N varnishes are
breathable so they still allow oxidisation
of the paint to continue? I haven’t had
any complaints of cracking or anything
with my paintings (touch wood!) and I
have to varnish them before they get
sent to customers as it wouldn’t be
feasible for me to ask them to send
them back for a final varnish in 6
months, but I do worry that I’m not
waiting long enough and they won’t
stand the test of time. Do you think I’m
varnishing them too early (I wait until
they’re touch dry + 1-2 weeks, and
sometimes see if my fingernail leaves an
indent)? I’m just a little concerned as I
don’t want them cracking down the line
but I’m not sure how I can get them to
customers on time? I read earlier you
suggested adding a retouch varnish and
then getting it sent back for a final
varnish, but I don’t think that would work
for me especially as I am a new artist
starting out.
Thank you so much!!
Elysia
Hi Elysia
Oil paint dries by oxidation and that requires air being able to reach through all the layers. Varnish will seal the paint and prevent it finishing the hardening process. The time it takes for most oil paintings to dry sufficiently for them to be varnished is 3-6 months – three months for a very thin coat of paint, four months for a medium thin coat of paint and six months for not too thick paintings. Thick impasto oil paintings are outliers and need to wait for up to two years to stop being squishy under the dried skin.
The mediums you add, the paints you use, the colours you use of those paints, the absorbency of the surface your paint is on, the temperature and humidity of the room where it’s drying – all affect the drying time.
Yes, the thumbnail test is useful to estimate the hardness of the dried oil.
Another way to test dryness is to wait until the painting starts to look dull in colour and sheen, like it needs the varnish to reinvigorate it. This will usually take a few months.
A spray retouching varnish is a good choice for initial protection until you can apply a final picture varnish. Retouching varnish is varnish diluted with extra solvent. It is so thin that it can breathe rather than sealing it completely. I understand that Gamvar is modern synthetic varnish. Some people only use the retouching varnish and do not do a final varnish.
There are basically two things that can go wrong if you seal a painting before the oil paint is completely dry. The varnish will merge with the paint instead of being a separate layer and if the varnish ever yellows in the future and the owner wishes to have the varnish layer removed and a new layer applied, this will not be possible, because it is not sitting on top. The second problem is that the paint layer is not strong enough yet to withstand bumps and scratches, it is still soft and wobbly under the thin skin. If you seal it before it can absorb enough oxygen to form a strong molecular structure, then it is a more fragile surface than it would have been.
Hi Julie,
Thank you for your message, I think I
have been varnishing my paintings
too early then, oh dear! I do hope they
will be alright but I will make sure I
use Gamvar in the future if it’s similar
to a retouch varnish as that seems
like a better option.
I do have another question as well – I
paint on MDF board primed with 2-3
layers of gesso, then I apply a layer of
acrylic to create a coloured ground.
However, this time I was
experimenting with a piece and I
decided to use a layer of water
mixable oil mixed with some fast
drying medium instead of the acrylic
layer. I left it to dry overnight before
painting on it the next day. When I
painted over it with water mixable oil,
I noticed cracking as it started to dry.
The layers above were thicker than
the base layer of oil so perhaps it’s
something to do with not letting the
base dry for a week or so before
painting on top? The only other thing I
can think of is that I tried using some
hog hair brushes rather than
synthetic ones. It didn’t start to crack
as soon as I put it on, just as the
finished painting had begun to dry
overnight. It didn’t happen on the
thicker parts of the painting, the dark
green paint just seemed to be
cracking to reveal the water mixable
ground underneath.
Thanks!
Hi.
I can’t quite tell what you mean, I’m sorry. But I don’t see how it could be the brushes.
It probably has something to do with how much fast drying medium you used or how thickly you painted your ground.
Hello, I have been using Cobra water
mixable oils because for years I have
breathed in solvents, not good for
me. I painted on board, and linen not
using a medium. Its not drying. Can
you help? Thank you, Debra
Hi Debra
What medium are you using? Do you mean it is staying sticky or not drying? How long has it been?
Have you read my other articles about Water-Mixable Oils – they might answer some of your questions.
Cobra doesn’t dry as fast as they say. I love their paint and use it
quite often, but your paintings WILL be wet to the touch for weeks,
not days. And that’s without anything added to extend drying times.
Thanks Nick
I haven’t found that to be the case in my painting or tests. I’d be interested to know what you are thinning the paint with, how thick you are applying it and and what surface you are painting on.
Do you mean it is staying sticky or actually not drying? How long has it been?
Have you read my other articles about Water-Mixable Oils – they might answer some of your questions.