Thursday, August 19, 2010

Cobalt and some other blues

Cobalt is the other blue on my palette. It is an expensive color, but is worth it's price for its cool, clear, sky blue color. Cobalt blue is a heavy metal color and is toxic, so reasonable cleanliness is important. Available since the early 1800's cobalt blue has long been a staple on the artists palette. The blue in Maxfield Parish's work is cobalt blue. Ultramarine is my warmer blue and cobalt my cooler blue. Sometimes, as I said before, I use really high key mixtures of white and viridian to make a blue that looks like cerulean.

Prussian blue is a very dark almost black, blue color. Prussian blue is a color that was supposedly impermanent, however the manufacturers mark it as permanent. I use it sometimes because it has a greenish cast that I like because it looks old timey. Prussian blue has been replaced today (except with me) by pthalocyanine which I find difficult to control.

Cerulean blue (cobalt stanate) is a light, delicate, opaque, slightly greenish blue. It has become very expensive in recent years and many makers only provide a hue which is, as usual, totally unsatisfactory. This is a great color in skies.

Manganese blue, was a permanent green-blue that was available when I was a student but was found to cause nervous system diseases. Now unavailable, I have heard its loss lamented many times by older artists.

Pthalocyanine blue, is a permanent, extremely intense, slightly greenish blue. It will tint to green or violet and is used in printing and industry besides by artists. I don't often use it as I find its pigmenting strength a drawback, being so much more powerful than everything else on my palette. However it makes great greens. If I had no viridian I would choose pthalo to build greens.

Most of the blues with names like azure blue or other evocative names are mixtures of pthalo and white. If you don't know what a blue that you see on a color makers list is, chances are reading the label will reveal it as a pthalo mixture. It is an inexpensive pigment and you could paint your whole house with about a quart if it was thinned properly.
Pthalo is used to make cerulean hue, viridian hue, cobalt blue hue, ocean blue, anteater blue, and just about every other "mystery blue". It is best to buy only named, single pigment colors, like cadmium red or ultramarine blue, rather than, hyacinth cerise deep or moonlight blue. The colormakers market dozens of these romantically named mixtures, mostly for the hobby market and students. If you like those colors you can mix them yourself on your palette and get more variation within that color yourself.

25 comments:

Marko said...

Stapleton

Many years ago I ran a pottery supplies shop...from time to time we would get painters in to buy some of the raw metal oxides used in ceramic glazes to use in their paint formulas... Cobalt Oxide (intense blue/black), Cobalt Carbonate(Pink Violet), Manganese Dioxide and of course the Oxides of Iron (red browns)etc. were some of the colours used. I am not sure of the usability of these, but these people kept coming back.... maybe some ambitious painters would let us into how they used them.
The only painter that ever told me the basics of how he did it, said that the oxide colours were mixed a glasseous powder called Frit, a fluxing medium used as a basis for many earthenware glazes, he would fire the mix to its temperature and when fully melted he would grind the resultant coloured "glass" to an extremely fine powder in a homemade ball mill , similar to what is used in lapidary to polish stones etc., then he would mix with his oils that he used for the carrier.
I always found it very interesting how he said he did it... but most of us just buy their paints ready to go...it is all fun in the end...and maybe a touch of dedication.

Regards
Marko

mariandioguardi.com said...

I only go to pthaylo blues and greens when nothing else will do. The tube of pthaylo I bought in1989 is still in with me ( and I have used it).a very little will go along long way.

Bill said...

Yeah pthalo is like a nuclear bomb, when I put any on my palette, it's typical to eventually find it all over everything, into every color, on me, my brush handles, etc. It's worse than glitter. Use with caution. I might take a little out of the tube with a toothpick or something to mix with. I think I've had my tube of it for about 30 years now.

Michael Chesley Johnson said...

Vasari has true Manganese Blue. They say on their website: "No longer produced, this genuine transparent, icy blue is without equal. After a long search, we were able to obtain enough pigment for several batches."

$45 for a 40ml tube. Yikes!

Michael Chesley Johnson said...

Oops, forgot the link:

http://www.shopvasaricolors.com/IBS/SimpleCat/Product/asp/hierarchy/00/product-id/49454.html

Philip Koch said...

Pthaylo blue mixed with raw umber can create really rich blacks for you. I love it. Yes you do have to be REALLY careful with it and keep it in its own little corner of your palette. If it spreads, stop everything and clean the whole area up. It's sort of like shaking hands with the devil, you just have to count you fingers afterward.

billspaintingmn said...

Pthaylo can jump 5 feet in any direction, but yes it does have an old timey look.
I remember a Perish Blue,by winsor & newton. I may still have a tube of it.

Bob Carter said...

Nice nuclear fission chain reaction diagram, Stape. Definitely makes me think of phthalo blue, the nuclear option on my palette. After fighting it for several years, I finally made my peace with phthalo blue and found I could tame it. It now happily resides at the end of the line of my paint blobs, where it won’t infect the others (talk about a chain reaction!). I find it really useful for water, and have even used it straight for dark blue low lights in ripples. I find the greens it makes with cadmium yellows a bit acidic, more like paint out of a can. So I’m more apt to use ultramarine for foliage greens. The red in ultramarine steps on the green a bit, which to my eye is more convincing. Phthalo blue makes a good near black when mixed with cadmium red deep (my cad red). Some years ago I was bowsing in Utrecht, and their Brilliant Blue caught my eye (speaking of romantically named hues). Wondering what the heck such a thing could be, I was surprised to read that it was a mix of PB29 (ultramarine - a warm blue) and PB15 (phthalo - a cool blue). That seemed illogical to me. Rather than buy the stuff, I went home and played with mixtures of ultramarine, phthalo, and white and found I could hit some really accurate sky notes. I now routinely use that combination for clear blue skies. Because of the different tinting strengths, the mix is mostly ultramarine with only a touch of phthalo, and of course a lot of white.

Bob Carter said...

Correction - I meant to say that phthalo is a warm blue (has yellow in it) and ultramarine is a cooler blue (has red in it). The problem is that I feel warmer about ultramarine and cooler about phthalo. :-)

jeff said...

About a year ago I found a couple of boxes of Old Holland Manganese Blue, six tubes, for about $40.

I use it from time to time.
Personally I prefer Cerulean and have also found some great buys on EBay.
WB 150ml for about $30.

It's getting harder finding these deals these days, but if you keep looking you can find some good deals on these expensive blues.

Vasari does make good paint but the cost for all the high chroma paints is out in the stratosphere.

Kyle V Thomas said...

Old Holland makes a Manganese Blue. I discovered this in art school. As far as I know, this is a true manganese.

If you ever find yourself in Arizona, let me know. We'll go paint and then we'll go drink.

McKinneyArtist said...

Every time my Aunt sees a tv show on clutter, I think she brings me more of her stuff. Todays posting made me look into my boxes of paints- only kept the ones that would open and paint would move. Here are some that may be antiques, you tell me. Paper wrapper oil colour London and in little letters it has Winsor & Newton (several tubes different colors). Grumbacher Cobalt Blue 37ml and Grumbacher Manganese Blue 37ml. Also found 2 tubes of Winsor & Newton Cobalt Violet Hue (Manganese Violet) <- thats on the label 37ml, I gave one of these tubes to my teach Susan L. , who you said put butter on my shoes.

Will I have to come North of the Mason Dixon Line to fine out about the butter deal? When will you list 2011 workshops? Best if I start saving empty cans now, hear everything cost a lot up there.

McKinneyArtist said...

PS on the tube of Manganese Violet on front has price $2.95. On the back it states Vehicle: Pure Linseed Oil Pigment Manganese Phosphate (PV16) Then it warns about Nervous System Damage and to contact Poison Control if swallowed.

Stapleton Kearns said...

Marko;
I have too much work to do to grind my own paint.
............Stape

Stapleton Kearns said...

Marian;.
A little dab'l do ya!
...............Stape

Stapleton Kearns said...

Bill;
Think containment.
................Stape

Stapleton Kearns said...

Michael;
Yikes 40.00 I will skip that.
..........Stape

Stapleton Kearns said...

Philip;
would ordinary dirt work as well as the umber?
...................Stape

Stapleton Kearns said...

Philip;
would ordinary dirt work as well as the umber?
...................Stape

Stapleton Kearns said...

bill:
I think that pthalo looks electric. Prussian looks old timey.
...............Stape

Stapleton Kearns said...

Bob;
The pthalo still looks too electric to me.I have another scientific offering for you tonight!
...............Stape

Stapleton Kearns said...

Jeff:
I don't buy cerulean much anymore but I prefer it also.
................Stape

Stapleton Kearns said...

Kyle;
I can't afford Old Holland or strong drink.
................Stape

Stapleton Kearns said...

McKinney;
Would you e-mail me an image of those. It would be fun to see them.
......................Stape

Bill said...

Stapleton: Trust but verify?