The Mural Printer's Bible:
The Mural Printer's Bible:
OK, here is my personal lowdown on large print and mural prints in a wet darkroom, this took several years of research....
Ilford makes both standard Multigrade and Warmtone Multigrade fiber based and RC paper in 42", 50" and 56" rolls. They also make just RC in 30" rolls. Some of the rolls have minimum orders of 10-15 that will add up to thousands of dollars, others don't. The only 30x40 paper they make is standard Multigrade in 50 sheet boxes at $826 and it is special order taking about two months. The best value is the 42" x 98 foot roll of standard Multigrade fiber in glossy at less than $500 and it is in stock, that is what I plan on doing 32" x 42" from, it can be found
here.
PAPER HANDLING:
Another thing to be very aware of is that above 20x24, fiber based paper gets heavy when wet, can expand a bit and can tear or crease super easy when moving it about. Currently, my small but very efficient darkroom can easily handle up to 20x24 with plans to do wall projected 30x40's. I make prints up to 16x20 in trays and use a Jobo 3063 drum on a Beseler motor base for my 20x24 prints. Since RC paper does not expand, the drum will take that size, but you have to trim about 3/4" off the 24" side of fiber to safely take the 2.5% expansion into account with a 3063 drum. Otherwise, you get a corrugated effect as it buckles. While tray processing of larger than 30x40 sizes does happen, it takes up an enormous amount of room.
To be able to handle the larger 30x40" sized paper, I am constructing a larger drum out of thinwall PVC pipe. It will actually be able to handle up to 32" x 48" prints which makes it somewhat more flexible in overall use. But it will require a custom motor base as it is still pretty heavy, about 8 pounds compared to the Jobo 3063 at 1/2 a pound. It is pictured in the attachment below. The upside of drum over tray processing of paper is it takes up less room, no fumes from large trays of chemistry, less chemistry used & can be done in daylight. The downside is you can not see the progress and have to really nail your test strips which should also be souped in a drum like the small Jobo Testdrum who's sole purpose is such.
LENSES:
One other thing to consider is what enlarging lenses you will be using for what format. For 4x5, a standard and relatively cheap 150mm 5.6 Rodagon or modern Schneider Componon 150 will get you up to 40x50 max. But for 35mm or medium format, you will either have to drum scan and get a 4x5 LVT made or stick to prints no larger than 28" wide for 35mm and 40" wide from 6x7 even from Rodagon Apo glass. Larger prints can be had with Rodenstock Rodagon 50mm & 105mm "G" mural lenses which are incredibly hard to find used and are no longer made....it took me years to find mine. They also are somewhat of a specialist lens as they are not good at all at smaller sizes. To go much larger than 30x40 with 4x5, you should use either a 150mm Rodagon G or a 150mm F/4 Rodagon Apo-N which I have the latter of, again, very hard to find now that more people are building out fine art darkrooms with top of the line stuff. Here is a great breakout of
Rodenstock enlarging lenses and what they can or can not do in terms of size.
ALIGNMENTS:
The other thing...and perhaps more important than the lens is that both enlarger alignment & film and paper flatness are critical for prints larger than 16x20 in my experience. I use a combination of anti-newton ring glass carriers with masks, a negaflat carrier for 4x5 and custom made magnetic easels. In the other photo attached is my baseboard converted to be magnetic, using 1" strips of cut plexiglass and regular magnets on my baseboard covered in thin sheet metal painted flat white. This is especially handy for curl prone fiber based paper and makes centering the image on larger paper easier in my confined space. I use a
laser alignment tool for any time I change the enlarger height more than a few inches, it really does help. Also, some enlargers are easier to align than others. For example, my Beseler 45MX is ok, has one adjustment for the lens stage and one for the overall angle of the head. But my mural enlarger is being made out of the bellows assembly of a Beseler CB7 enlarger which is far more robust and has fine adjustments not unlike that of a monorail view camera. It also has motorized focus which will incorporate a remote paddle for being able to hit focus while at the wall away from the enlarger. It will be horizontally mounted and speaking of which, it makes more sense than large prints on the floor in case you spill or drop something and the larger area of paper collecting other foreign objects like dust.
LIGHT SOURCES:
In terms of light sources for larger prints, you have to either use a strong condenser lamp house or an Aristo D2-HI Cold light with the brighter output bulb in my opinion. I have both but use the latter at the moment and will be moving that over to my mural enlarger with it's dedicated
RH Designs Stopclock Vario Compensating timer while a newly acquired Beseler 45S Dichro head fills the spot on the upright enlarger. And by the way, you do not need to spend a lot of time trying to find a D2-HI head when a regular one will do as Voltarc took over Aristo a few years ago and only offer the higher output V54 light source as a replacement for any of the models, I believe they are $170 the last time I checked. Contact Louise Kessler at
Voltarc go get current pricing and order info..
LIGHT SPILL:
One last note is that you need to "flock" as much as you can when printing large as light spilling on the walls, out of the enlarger and even the paper reflecting light back up off the ceiling can degrade the contrast a little or up to a full grade. I will be using Duvetine or "Commando Cloth" to make black light paths for larger prints when wall projecting.
So in conclusion, while there is lots of industry standard stuff to get you easily to prints up to 20x24, when you get much above that, it virtually disappears thereby necessitating a more home brew approach. If you like that kind of thing like I do, it can be fun overcoming these obstacles.
Two mural printers that are well respected are Clyde Butcher and Bob Carnie. Clyde uses a process camera as a horizontal mural enlarger:
http://www.clydebutcher.com/
Bob Carnie can be found on both APUG and LFPF and is a wealth of knowledge. Hope this helps...
