Oil print question

[Kami-the-Trout]

I've been playing around with oil prints for fun, and have a question.

I've been coating watercolour paper with Knox gelatin, brushing on 3% potassium dichromate and contact printing 4x5 negs under UV.

My first question -- how do you know what the proper UV exposure is? I've exposed negs from six to 12 minutes and can't see any difference in the matrix that comes out.

There is a faint brown image on all of them, but I can't see detail in them, until I start to ink them up, after which details starts to emerge. I'm not having a lot of success inking yet ( I didn't expect to), the ink seems to smudge up pretty heavy in the dark parts and muddies up in the highlights. There is an image there, but it's not very good.

Am I overexposing the matrix, or underexposing? How can I tell?

As well, after brushing on the potass. dischrom solution, the book I have says the paper becomes light sensitive as it dries. Is the drying print sensitive to ALL light, or just UV? I'm used to the other alt processes that allow us to work under faint tungsten. Is that a bad idea when drying oil print paper?

Any help greatly appreciated.

 

[Toffle]

You might want to ask Marianne (Mayfair710). She has been doing some stunning oil prints lately, though what she describes sounds much different from what you are doing.

Cheers,

 

[Dana Sullivan]

Knox gelatin might be too soft. It's around 100-120 bloom hardness, where a typical photo grade gelatin is around 250 bloom. The harder gelatin might offer more 'bite' for the ink.

You most likely won't see much more than a faint ghost image after removing the image from the UV box. I don't know about exposure times, though.

I've heard that oil prints can benefit from a half tone screen of 150 dpi +/-. Apparently breaking the image up into dots will also help the ink adhere, because you're giving it a lot of sharp edges to work with.

The dichromate-coated paper is more light sensitive than say a cyanotype or platinum/palladium coated paper. You may be experiencing some fogging using tungsten lighting, so try to dry your paper in the dark. A safelight isn't really necessary, just try to limit the sensitized paper's exposure to light as best you can without being too crazy about it.

Hope that helps.

-Dana

I've been playing around with oil prints for fun, and have a question.

I've been coating watercolour paper with Knox gelatin, brushing on 3% potassium dichromate and contact printing 4x5 negs under UV.

My first question -- how do you know what the proper UV exposure is? I've exposed negs from six to 12 minutes and can't see any difference in the matrix that comes out.

There is a faint brown image on all of them, but I can't see detail in them, until I start to ink them up, after which details starts to emerge. I'm not having a lot of success inking yet ( I didn't expect to), the ink seems to smudge up pretty heavy in the dark parts and muddies up in the highlights. There is an image there, but it's not very good.

Am I overexposing the matrix, or underexposing? How can I tell?

As well, after brushing on the potass. dischrom solution, the book I have says the paper becomes light sensitive as it dries. Is the drying print sensitive to ALL light, or just UV? I'm used to the other alt processes that allow us to work under faint tungsten. Is that a bad idea when drying oil print paper?

Any help greatly appreciated.

 

[holmburgers]

Anyone here experimenting with oil prints? At the moment, I just want to ink of some dichromated-gelatin matrices; not yet wanting to fiddle with bromoil or transferring the image.

I've got Sumi ink and Calligrapher's ink, any idea if either will work? Are they oily enough?

Cheers!

 

[gandolfi]

wow - a lot of questions, impossible to answer....

KAmi: it all depends.... on the density of the negative - the distance/power of the UV light - how many layers of gelatine - and so on...

you have to test this.. 4x5 isn't big, so make different exposures on the same negative (motive) - then you'll see...

Dana: drying in darkness is good, but be aware of the "dark process"... don't wait too long before using the matrix - it will harden slowly - also in the dark..

Contrast can somewhat be controlled when inking the image - softer ink: more grey tones - harder ink: higher contrast..

Holmburgers: test the colours - I have sometimes bought impossible oils - sometimes perfect... it is never easy to know before trying.... (but as a thumb rule I would say that lithographic oils are easier than "normal" oil colours...)

And why would you "just want to ink some dichromated gelatine matrices"?
My experience is, that this is much harder than making bromoils!

 

[David Hatton]

My method for oil prints

Hi,
This was passed on to me by an expert - and it works. Get a nice strong paper, I use Fabriano 50 300 lb. Three coats of 5% gelatine - the first one may benefit from a little hardener but I found not strictly necessary. Take a soft brus - Hake I use - and flood the paper with pottasium dichromate about a 6 or 7% solution. Get plenty on the paper and keep brushing until most or all of the chemcal is absorbed by the gelatin. Leave to dry. Expose under your test neg for about 3 - 4 mins. You should see a pretty good brownish printout after exposure. Rinse well with water to get rid of the dichromate and allow to dry out completely. This sounds daft but once dry, soak it in water to swell the gelatine. Pat dry to get excess water from the matrix. You may have to re-wet the matrix as your oiling progresses. For this process the oil pigmet needs to bee really stiff/tacky. You can buy stiffeners but better to use a stiff oil. After that all you need to do is roll on/off the ink until you have a masterpiece..Easy innit!

 

[David Hatton]

I've got Sumi ink and Calligrapher's ink, any idea if either will work? Are they oily enough?

Sorry, they won't work at all. You really need litho ink.

 

[holmburgers]

Hey thanks much guys.

David, that sounds nice & easy! And to also answer gandolfi's question, the reason I want to just ink up some DCG matrices is because I will have some excess matrices for my dye-imbition experiements, and I don't want to go out of my way to buy the right paper, buy the chemicals for the bleach, etc.

All in due time, but I was attracted to how simple the classic "oil" process sounded.

Also, I'm completely new to inks, oils, everything regarding graphic arts in this manner. I don't even know what lithographic oils are let alone what's "normal"!

edit: ahh, beat me to it... thanks David.

 

[gandolfi]

a word of warning! ;-)

If you think it is easy, then beware of the oilprint God's (and later the bromoil God's..).. They will slap you so hard!

about the oilpaint: You dont need the litographic inks.... (made for printing) - you can use oil paint (made for painting), but as I said - some work like a charm - some not....

David said: "You can buy stiffeners but better to use a stiff oil."...

yes and no - even when using lithographic ink, it is (in my experience) not still enough!
I always use ex magnesium carbonalt - a powder you can mix in the ink to make it stiffer. Also because you - as said - can alter contrast with the stiffness of the oil...

again: simple doesn't always mean easy....

 

[holmburgers]

Well, I'm an atheist, so I'll give it a go and see what happens. Maybe it'll convert me!

 

[alexhill]

I haven't done an oil print (yet) but I do now a little bit about paint that might help.

The difference between the different oil based inks/paints is usually the binder they are mixed with. I've heard that you can use oil paint, but it is a very different constancy from a litho or intaglio ink. You could try adding sun thickened or polymerized linseed oil to artists grade oil paint if you absolutely can not find a litho or oil based etching ink. Also litho inks often have resins and waxes to further their water resistant properties.

Also litho inks (tend to) use pigment which will not be soluble in water. Oil paint isn't expected to get wet, so research into specify pigments is needed. Another thing to avoid is 'water soluble oils' sounds obvious, but they would desolve in water.

In printmaking classes we would often take a xerox copy, saturate it with gum arabic, then ink it up with oil based intaglio inks just like an oil print is done. So I wouldn't worry too much about using an intaglio ink in place of litho.

Anyways, that's my 2 cents, hope it was helpful.

 

[holmburgers]

Thanks alex, it does help. I'm curious about this xerox print method...

 

[alexhill]

Glad I could help. The xerox is super easy to do, the only downside is it can only reproduce solid tones and not gradations. I never tried using a photocopy of a halftone, so that could be an option.

Your going to need a decent amount of gum arabic. The quality of the gum arabic isn't so important, and I would definitely not be using anything that looks like this . Its a much higher end gum arabic than you need, get the cheaper printmaking grade if possible. Also you need an oil based ink (or paint if your thicken it)

First thing it to make a xerox (toner based copy) of whatever you want to print. Place it copy side up on a glass surface. You want to saturate the xerox copy with the gum and rub it in gently. It should look soaked. Then you spritz the copy with tap water. Prepare your ink by warming it up, then preparing a even coating onto your glass pallet and roller.

Once you've got your roller evenly inked, you will roll it across your xerox 'plate' once. Then very, very softly roll it across a paper towel to remove any water on it. This is to prevent contaminating your ink. Re-ink and roll across a new segment of your xerox, roll along a paper towel, ect. Once you've inked in one direction, turn the 'plate' 90 degrees and ink across your previous marks. You may have to lightly spritz your 'plate' with water during the inking process.

Once you are sure you have an even coating of ink, you carefully lift the 'plate' up and put it ink side down onto whatever your receiving surface is. We would use a press which is set to put a lot of pressure (similar to intaglio prints, or litho). But if your careful and take your time you should be able to use a large spoon and burnish the image into good contact. Depending on how fragile the plate is, you might want to put a medium weight printmaking paper between the spoon and the xerox plate. I'm thinking like a rives bfk, or stonehenge (both which would be a great paper to receive the print from the plate). Its ok to lift a corner to see where you've missed, as long as the rest plate doesn't move.

This plate should be durable enough to yield a few prints, but the key is to keep it wet by spiriting it just prior to putting a new coat of ink.

I'd be happy to answer any more questions about this. We would usually use this for putting a pre-made pattern on linoleum, or perhaps as a temporary etching resist. Its not really a medium in its own right due to the relative fragility of the plate and short lifespan. That said, its still wiked cool and a useful tool

 

[yashasvi bhuta]

well you can also make your own ink it's a very simple process and a very cheap way to get things done

http://in.groups.yahoo.com/neo/groups/oilprinting