A Few Questions About Photogravure

[Ross Chambers]

The label on the can said "Worms" I didn't mean to open it. Please proceed without me :-)

Ross

[Ross Chambers]

The label on the can said "Worms" I didn't mean to open it. Please proceed without me :-)

Ross

[squinonescolon]

I would stick with the trays, never tried the vertical tank, but as you say you would need at 3-4. So either way. You can tell if you're underexposed, overexposure is trickier and you really need more experience to see it, you should be able to tell gross overexposure. All bets are off until the plate hits the acid, but once you figure out all the variables it should be pretty automatic and you'll notice when you did something wrong, and what you did right away, but by that point the copper is ruined, so there you go. You also need a dedicated aquatint box. You can't mix the PICCO with any other grounds. I would buy a bag of PICCO from the distributor instead of from Cape Fear because you'll have to charge a newly cleaned box and depending on how big they are it can take quite a bit of ground. I have a large box(8'x4'x4') based on Crown Point Press box, it takes about 10 tablespoons to fully charge, which might be a quarter of a pound, and a smaller one(7'x2'x2') that charges with just 4. Every time you dust you charge with about three spoons, it would get expensive to buy by the pound. I think my bag was something like $150 and is somewhere around 50 pounds.

Also, the tissue needs to dry in the dark at an even temperature for at least 4-6 hours. Nobody can't use the darkroom during that time for obvious reasons, I built a drying cabinet so I could regain use of the darkroom. You can make a batch and freeze, according to all reports it should last indefinitely, but I've never tried it. Or you can place in a dedicated refrigerator(it has to be dedicated, you can't have anything containing dichromate next to food, you'll get poisoned or poison someone) for a day, that I do sometimes, and never had problems.

If you do the aquatint over the tissue you have to re-humidify the tissue for at least six hours--eight is more prudent--to 68 relative humidity for Phoenix, if you do it the aquatint under, 4-6 hours. Again the darkroom is the perfect place for this, or you can build a humidor for the plates(recomended).
So if you're counting the hours, it takes at least two days for a plate from beginning to end when you're dealing with dustgrain aquatint, can be less if you do the screens, but I wouldn't try to cut the time until you're experienced, no need to rush things.

Best papers are Somerset Satin with Gampi 'Chine-Colle' or Revere Silk by itself. Start with Revere, its beautiful paper. It takes experience to do Chine-Colle, or you can get your friends to do that for you. I've tried a thousand combinations, those are the papers that look the most 'photographic'.
The "Demistifying" book is the bible now. You don't need another book for a while.

My materials are:
Pot. Dichromate (Not Bichromate) To make 3.5% solution
Isopropyl Acohol
A stable source of 112F degree water to develop
Degreaser for the plates
Contact tissue to mask the back of the plates
3m Magick tape to mask near the tissue.
Marker to create a solid mask line around the tissue (in the book) or thinned liquid asphaltum
Large roll Ulano Masking material to create an edge around the positive
Stouffer 21 Step wedges (at least 2) label them in black marker on the top so you know which ones you used to make exposures, they vary slightly.
A Baume Meter that can measure from 39 Baume to 43, you can get two if you can't find one that spans that scale
Hunt™ ROTOGRAVURE IRON 48° Baume Blue Comes in 5 gallon pails, I think about $150, season it with copper shavings.
Alcohol meter for measuring alcohol gravity.
Humidifier that can cover your darkroom.
Hygrometer (measures humidity)
Plexiglass, larger than your largest plate by a couple of inches.
At least 2 thermometers, one glass only, to measure the ferric temperature, another one (as sturdy as possible) for the developing bath.

[qwfwq]

Thanks for the advice.

Any handling advice for the gravure tissue? just got my order today from cape fear.

[Hexavalent]

My materials are:
Pot. Dichromate (Not Bichromate) To make 3.5% solution

Bichromate = Dichromate. Only the spelling differs.

[artonpaper]

I'm a beginner, but I can give a couple of points of advice here. I took a workshop a year ago with Lothar Osterburg. Hew showed us a number of different ways to achieve similar results. First, one can use traditional aquatint, or an aquatint screen. Some used one, some the other. I used the screen. I don't think the results were noticeably different. After the tissue is exposed to the film positive, the fiml is removed and and the tissue is given two quick exposures to the with the aquatint screen in contact with the tissue. It is shifted between the two exposures to make it less apparent. We used Bostick and Sullivan's gravure tissue which worked quite well. If you don't have room for a light bank, you can use metal halide bulbs. I use a 1000 watt plant light for palladium, gum, and carbon printing. Regarding dichromate, have B&S dilute it for you and then it doesn't require dichromate. You can dilute further if need be. Here in NY it can be picked up in powder form from B&H or Adorama. I moved recently and my notes are still packed away. Sorry I can't be more precise.

[squinonescolon]

Ask Jennifer for the latest on processing the tissue. She's done many tests on that material.

[Cape Fear]

Hi everyone,
I just announced the Feb workshop in the workshop forum. I make most of my plates with the Picco, dusting under and not over. If your dust box is not too leaky a pound of Picco should go a long way. I will combine shipping on more than one pound, just call me.

The plates need to be etched in flat trays, there is no better way because you need to watch what is happening. It is more fun that way too and you make very intuitive and visual decisions here. The etching is my favorite part of the process.

I also recently did a breakdown of costs of gravure using the Phoenix Gravure small roll price with 16 oz. roofing copper and you can make an 8x10" gravure much less than you might believe. Roofing copper is a great option for beginners as well as seasoned etchers who etch small scale plates and want to keep the cost of gravure down. Check out the details here: http://www.capefearpress.com/phoenixgravurepr.html

Artcraft chemicals is another good source for dichromate.

As for gravure vs other photo intaglio processes, etched copper gravure is the only gravure. Many others have similar concerns about this. Please see more here: http://www.capefearpress.com/photointagliodef.html

Thanks for the referral Steven!

Jennifer

attached is one of my recent gravures made with Picco: