5 grams Ferrous Sulphate (dissolve in acidified water, a dropper of vinegar) 20 grams Sodium Citrate top off with to 70ml Add 1 dropper of 10% K Bromide. (Add a dropper of Silver Nitrate before first use.)
Develop for 10 – 30 minutes. Keep and reuse.
This is a modified formula of the Eastman formula in Ernst Lietze’s Modern Heliographic Formula. It lessens the overdevelopment risk of the paper developer/exhausted fixer combinations, and helps with frilling problems.
Paper: Clearprint Heavy Vellum (mark the backside)
Iodizer: Pre Silver 3.8% – Rod Coat (single) K Iodide 5.5% – 3 minute bath (can be reused) 1 hour wash
Sensitizer: (adhere paper to plate) 1 dropper (~0.5ml) 3.8% Silver Nitrate 2 droppers (1ml) vinegar Rod Coat – leave until matte dry Rinse with D. H20 twice air dry (bloating produce contamination effects in development)
Exposure 1 & 1/2 minute @ f/~11 (dim sun)
Development ~100ml Saturated Gallic Acid 1 dropper (~0.5ml) 3.8% Silver Nitrate 30 minutes bath (vinegar can be added to slow development)
I’ve been surprised to find such little information about making digital negatives with this printer, as it’s been such a popular printer for so long (almost a decade?). I recently purchased one with its holiday rebate that dropped its price to $150 with a large box of paper, with the intention of printing digital negatives.
After testing, I would much rather have purchased a printer that uses pigment based inks, preferably an Epson printer compatible with QTR. The densest ink load this printer can produce is around a 1.8. Which is dense enough to produce negatives with enough UV light blocking capability for most processes. But for processes that require a more demanding opacity (salted paper/albumen prints), this printer will not be effective.
But for those who already own this printer, or can’t afford a higher end printer, these are the settings which I found produces an appropriate negative for cyanotype printing. It follows Christina Z Anderson’s Digital Negative instructions on Freestyle Photo’s website. (I’ve tested Dan Burkholder’s old colorized negative technique, but I find this method uses too much cyan and magenta inks in the midtones that results in an unpleasant grainy texture.)
The setting below utilize more yellow and light gray inks that produces much smoother separations. In the main print menu, select Glossy II and the highest quality (1) setting. Below are the settings for manual color adjustments.
I use Precision Colors Refillable inks, so I use their Printing Profile.
For linearization, I prefer this 101 step scale from Peter Mrhar’s website. I stretched it to fit as large as possible on a scrap sheet of transparency. I prefer this step scale because it is easy to determine the darkest tone of the negative, by covering the 10-row with a ruler and looking for distinctions of the gaps between the blocks in the 0 row begin. In my case, the line between the 6th and 7th blocks is not visible, but it is visible between the 7th and 8th blocks. Therefore, the maximum tone of the negative needed is the tone of the 7th block, which translates to 237 on the photoshop light curve.
The curve that linearizes a negative for cyanotype printing needs to be lower than the -50 contrast setting of the printer.
For convenience, I only flip and invert the image in the Output menu of the main print settings. This is done by checking Negative, Emulsion Down and choose a background color 0,0,0 RGB. You may add a masking border and registration marks in this dialog box if needed.
This was my research during an internship at Renaissance Press a few summers ago. My goal was to quicken the development of calotype negatives to a few minutes instead of the 30-120 minutes necessary to build up enough density with gallic acid. (Pyrogallol is too aggressive and produces too coarse of grains for my taste.) Thus I began experimenting with Metol developers.
I would consider this research incomplete, and will begin more tests soon.
3.25″ x 4.25″ calotype negative
Bienfang Vellum (100% rag)
I am currently trying out a new calotype recipe, and need to fine-tune its exposures. Due to the size of the calotype, the screen pattern of the paper is very prominent in the image. So I decided to make a comparison of a waxed and unwaxed calotype.
My waxing method is as follows. First saturate 2 sheets of newsprint larger than the calotype with paraffin wax using an iron set to medium heat. The negative is placed between the saturated newsprint, and, and that sandwich between two sheets of dry newsprint. (Ironing the saturated papers directly builds up black marks that can transfer onto the negative.) Iron the pile until the negative become completely transparent. It is easily visible when the negative is back-lit. Then iron the negative between two sheets of newsprint until the excess wax is removed.
Left: Silver gelatin print of unwaxed calotype. (10 seconds @ f/2.8 no filter)
Right: Silver gelatin contact print of waxed calotype. (2 seconds @ f/2.8 no filter)
Paper prep is important for most historic processes. An additional sizing step before the light sensitive processes can really improve the print quality, and remedy problems. Gelatin is a commonly used sizing agent with a hardening agent like chrome alum or formaldehyde that polymerizes the gelatin, rendering it insoluble. I’ve experimented with plain alum (Potassium Aluminum Sulfate) from grocery stores as a hardener with success, even with carbon printing. Pictured is two different sizing techniques that I’m currently testing.
Left: Floated on a hot bath of 5% gelatin, 1.5% alum, 15% vinegar.
Right: Two bath sizing. Submerged in 5% gelatin . Hung to dry. Then submerged in 3% alum bath for 15 minutes.
The two bath sizing has a less textured, less glossy, and clearer sizing. The one bath sizing has a thicker coating, and a yellowish discoloration. Perhaps just more noticeable because the thickness of the coating, perhaps the vinegar reacts to the gel/alum. The vinegar addition is necessary as the gel/alum bath immediately thickens to the point of being inoperable. Vinegar will remedy this, even after the effect takes place.
Rediscovering some gifted film (Kodak Ektachrome 64, expired in 1996) and newly found RA-4 chemistry, and worrying about a lack of darkroom in the future, I thought I’d use some hoarded materials, and do some experiments processing color film. And I’m happy (somewhat) with the results. I overexposed the film 2 stops, and I think I still underdeveloped the first development (1:3 Dektol for 6minutes @ 100F) since the highlights still appear somewhat dull.
The RA-4 is a 3 part concentration replenishing kit for 25L tanks, silver pixel. I did a couple tests to find what concentrations to mix them, to process C-41 films at 3:15 minutes. 10ml part A, 5ml part B, 10ml Part C to 300ml water. For the blix, a separate bleach: a slightly akali ferricyanide, and fix bath: sprint 1:4, 5 minutes each. This gives me acceptable results to scan, so I’m not too worry about its archival properties. Also, according to smarter photo engineers on APUG, straying from the standard formulas voids the archival properties of the slide film.
After the first stop bath, (30-35g soda ash in 500ml vinegar) I turn and keep the lights on. I rinse the film for a little longer after the color is removed for the tray, expose the film to 300W bulbs, both sides for about a minute a piece, nothing exact. I then color develop in the formula above for 3:15, then again stop and rinse. After, bleach and fix for 5 minutes each rinsing in between. Finally, I wash the film for 5 minutes and stabilize with Sprint’s stabilizer for a minute.