foam brush paper coating question

You know that none of these methods are used to get high quality silver gelatin coatings, right?

In fact, the method used to get high quality silver gelatin coatings can be used to improve other methods of coating alternate photo sensitive materials.

At the research divisions of all major manufacturers, we have developed a unique method of coating that gives near production quality coatings from hand coated materials as small as 2x3 but as large as 11x14.

Now, I am going to be the first to admit that brushes add an art like look and quality to a print, but if you want near production quailty, the coating blade is the method to use. I have been using my sample blades for about 2 months now, and will have soon, in-hand, a batch of blades for 4x5 and 8x10. I will be using them at the workshop to instruct people and show how this method can be used as an alternative to all that has been described above.

This basic method has been in use for high quality coating for nearly 100 years. I am really surprised that this did not propagate to the general coating public out there, but I have seen no one using anything like this.

You will see them soon.

PE

Can we see what one looks like now?


Wayne

Photo Engineer said:

You know that none of these methods are used to get high quality silver gelatin coatings, right?

In fact, the method used to get high quality silver gelatin coatings can be used to improve other methods of coating alternate photo sensitive materials.

At the research divisions of all major manufacturers, we have developed a unique method of coating that gives near production quality coatings from hand coated materials as small as 2x3 but as large as 11x14.

Now, I am going to be the first to admit that brushes add an art like look and quality to a print, but if you want near production quailty, the coating blade is the method to use. I have been using my sample blades for about 2 months now, and will have soon, in-hand, a batch of blades for 4x5 and 8x10. I will be using them at the workshop to instruct people and show how this method can be used as an alternative to all that has been described above.

This basic method has been in use for high quality coating for nearly 100 years. I am really surprised that this did not propagate to the general coating public out there, but I have seen no one using anything like this.

You will see them soon.

PE

Click to expand...

PE, It would be great if they would work, but the first thing I see is 4x5 and 8x10. That would be great for film, but many prints fall outside those sizes. Have you tried them on alt papers? It is not the brush stroke look that is that important but the ability to handle diminsionally unstable material. And to me that is at the basis for the whole what type of brush or coating device one should or can use conversation.

Can you describe your tool a little more? Does it hold the paper down as well as apply the coating? How big do you plan to go? is it adjustable?

As I change print sizes, I change the size of the brush. Small prints, 8x10 or less, I use a 2" brush, but for bigger images, I use up to a 4" brush for 30x40. I can't imagine coating a 30"x40" area with a 2" brush.

What is the failure rate? streaks? cleaning or changing emulsions?

Eric

The failure rate is less than 10% at 4x5 and increases to about 10% at 8x10. I have a prototype blade for 11x14 and there is no reason why a 16x20 blade cannot be built except for cost.

They do hold the paper down for uniform spread of materials from top to bottom and side to side resulting in a precise measurement of liquid delivered to the surface of the paper or film.

Cleaning involves a dip in hot water and a rinse with water then drying with a towel and you are ready for the next coating. These are stainless steel. The 4x5 blade weighs about 1lb (420 grams) and the 8x10 blade is about 2x heavier.

The amount of solution applied depends on gap width of the trailing edge of the blade and can be adujsted to whatever you wish. That way, you only need to make one coating, not multiple coatings.

I coat from .002" to 0.010" with no problem. The pictures I have posted here were coated at 0.005" (5 mil). At 5mil, the average 8x10 requires 12 ml of total solution, but the active ingredients may be adusted based on desired dmax and contrast.

It is related to the doctor blade used in early photo coating machines or to the coating blade used in the paint industry to check out varying thicknesses of paints. It is a precision instrument made of high quality stainless steel. I have avoided posting pictures as the only pictures I have currently are digital for rapid transmission to co-workers, and I don't wish to post them on APUG. I feel it to be detrimental to the goals of APUG, but necessary in the business world (so to speak and with apologies. Digital has a place, but not in art IMHO.).

Please forgive.

Anyhow, I have had 2 production batches fail due to various reasons beyond my control, otherwise things would be further advanced than they are. I expect the real delivery to be about the first week in April. I will have 5 blades of each size at the workshops.

PE

Photo Engineer said:

I have avoided posting pictures as the only pictures I have currently are digital for rapid transmission to co-workers, and I don't wish to post them on APUG. I feel it to be detrimental to the goals of APUG, but necessary in the business world (so to speak and with apologies. Digital has a place, but not in art IMHO.).


PE

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I don't think digital photographs of your coating blade should be a problem here at APUG since you aren't posting them in the galleries. Besides all images here at APUG are digital anyway.

My 2 cents,

Don Bryant

Speaking as a moderator, a digital representation of an analog product is - well, what APUG is about, really!

A picture in a thread to explain what the blades look like is not only acceptable, it's most appropriate.

Besides, I want to see what it looks like

Prototype Film blade

Ok then, here are two pictures of a prototype film blade. It makes 2 4x5 coated areas on one piece of 5" x 12" film and uses 6 ml of solution to coat that area when gapped at 5 mil.

This is the first anyone on the internet is seeing these.

Sorry for the flare from the flash, but it is rather dark here and the blades are highly polished.

PE

Photo Engineer said:

I coat from .002" to 0.010" with no problem. The pictures I have posted here were coated at 0.005" (5 mil). At 5mil, the average 8x10 requires 12 ml of total solution, but the active ingredients may be adusted based on desired dmax and contrast.PE

Click to expand...

Ok, I'm pretty new to this alternative process stuff. Well, actually, really new compared to most of you. So these may be really stupid questions. But I find that I've been using about 2-ml (maybe a skosh more or less) of sensitizer solution per coat on 8x10 VDBs, using Arches Platine (I've just did a few on Rising Stonehenge today, it's a lot more absorbent than Platine). I've been wondering about my Dmax as I print mostly on Azo which has very good Dmax and very rich blacks. So far I'm not close, but given that these VDBs are mat finish I'm not expecting similar (is that a correct expectation?). My prints do have a lot of scale, but it's shifted up more than I'm use to. I would like more Dmax, but I'm already getting some small pooling of solution at the edge of the print after 4 to 5 passes with a glass rod, so more solution doesn't seem to the answer. How does Photo Engineer use 12ml per 8x10? Should I be using much "thicker" coatings? I thought thin was better. What's more dominant in getting more Dmax (while retaining highlight detail), more coating, more print exposure, or higher contrast negatives?

Thanks. This is much more fun than using Ctrl-Print (but what about using giclee printing method for coating sensitizer, eh?)

TheFlyingCamera said:

at least get yourself a nice but inexpensive Hake brush

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If you want to use a Hake brush spend the money to get a good one.

Connoisseur brand hake brushs are the creme de la creme of hake brushs. From the first time to the last time you use one they won't shed - ever! They are soft and don't clump when wet. This is the only brand of hake brushes that I've used that isn't a piece of crap except for Winsor Newton brand which I think maybe the same brush.

I use my Connoisseur to coat cyanotype and gum only but you could use them for other processes. But they do come with a price, IOW they aren't inexpensive.


Check here for sizes and pricing.

http://www.c2f.com/html/productlist.asp?CategoryID=P-79318

The best glass rods are the ones sold by Bostick and Sullivan, simply because the handles give excellent control of the rod allowing light pressure to be used, resulting in strait coating passes.

For ferric salt based processes the magic brush can't be beaten.

middlecalf said:

Ok, I'm pretty new to this alternative process stuff. Well, actually, really new compared to most of you. So these may be really stupid questions. But I find that I've been using about 2-ml (maybe a skosh more or less) of sensitizer solution per coat on 8x10 VDBs, using Arches Platine (I've just did a few on Rising Stonehenge today, it's a lot more absorbent than Platine). I've been wondering about my Dmax as I print mostly on Azo which has very good Dmax and very rich blacks. So far I'm not close, but given that these VDBs are mat finish I'm not expecting similar (is that a correct expectation?). My prints do have a lot of scale, but it's shifted up more than I'm use to. I would like more Dmax, but I'm already getting some small pooling of solution at the edge of the print after 4 to 5 passes with a glass rod, so more solution doesn't seem to the answer. How does Photo Engineer use 12ml per 8x10? Should I be using much "thicker" coatings? I thought thin was better. What's more dominant in getting more Dmax (while retaining highlight detail), more coating, more print exposure, or higher contrast negatives?

Thanks. This is much more fun than using Ctrl-Print (but what about using giclee printing method for coating sensitizer, eh?)

Click to expand...

Well, I've coated VDB with these blades and they work well, but you have to have something to thicken the material as this relies on viscosity for proper spreading on the paper or film.

With this method, you can precisely control the amount of chemistry on each square meter of paper as well.

Glicee is a digital technique which is beyond the scope of this forum.

PE

middlecalf said:

How does Photo Engineer use 12ml per 8x10? Should I be using much "thicker" coatings? I thought thin was better. What's more dominant in getting more Dmax (while retaining highlight detail), more coating, more print exposure, or higher contrast negatives?

Click to expand...

The only way to get 12ml of solution on a piece of 8X10 paper is to use some additive that will increase its viscosity, gum or gelatin for example. Of course, this will make it more difficult to get a smooth coating.

You will not be able to get Dmax with Pt./Pd. as high as AZO with normal methods of printing. About the best anyone can do is a reflective density of around log 1.60, and that is not easy to achieve. Printing several layers might get the DMax up to 1.8, but for more than that I think you wil need to apply the sensitizer in a gelatin or gum emulsion that keeps the solution on the surface of the paper and gives it gloss. But that would significantly change the character of a Pt./Pd. print, when what many people really like is the flat matte look.

Sandy

Sandy;

By varying the paper surface type and the amount of gelatin / chemistry in my mix, I can get surfaces varying from high gloss to matte. I have also made coatings on canvas, vellum and watercolor papers with good results.

The final result in my case depends more on ratio of binder to chemistry and to the paper surface.

PE

The comment on giclee sparked a thought PE, have you ever tried spreading emulsion using a silkscreen? I'd think a polyester 300 mesh using a soft squeeegee might give a fairly even coat and is low tech enough for most folks to try for grins and giggles. The texture from the mesh would smooth down a bit on standing after application if the emulsion flows enough.

Gary;

I did silk screen printing back in HS. Yes, it works. You don't get the option to control the spread of chemistry, but it works.

BTW, the coating blades are now posted for sale on the Formulary web site.

PE