Print Developer Recommendation
From Silvergrain Research
Contents |
Introduction
Today's enlarging papers are designed to give intended results in a wide range of print developers. Therefore, many old tricks of fine tuning print developers are largely obsolete. The benefit of some exotic formulae are now more reliably obtained with straight-forward ascorbate developers. Those exotic developers often used toxic, expensive chemicals to achieve their goal, but with today's technology, all those harmful agents can be substituted with more common (and safer and often cheaper) agents and still maintain excellent image quality.
Standard workflow has also been simplified. For example, in old literature, two stage print development is often described as a way to control contrast. In this technique, exposed print is first processed in a standard or high contrast print developer for some time, followed by a low contrast developer. The contrast was controlled by adjusting the time spent in each developer. However, such a technique lost significance today, partly because of widespread use of variable contrast enlarging paper stock, and partly because such paper emulsions do not respond well to developer composition in the way old emulsions did.
That means that, if you aren't happy with your results, it is best to reconsider your paper selection first, and modify processing technique as a way to modulate their characteristics. One big variable in processing is toning and then print developer. So why print developer important? This is because, without a good standard print developer, it is impossible to make fair comparison of paper stocks, and the effect of toning treatment. What all these sum up to is the importance of all round print developer which works well with many paper stocks, so that a user can switch paper stock in the middle of a printing session.
Which Print Developer?
Most standard print developers are MQ or PQ developer with sulfite, bromide, carbonate and possibly benzotriazole. The composition of representive developers are very similar, with possible range of dilution factors considered.
| Neutral-tone print develoeprs | ||||
|---|---|---|---|---|
| AGFA 100 | Kodak D-72 | GAF 125 | Ilford ID-62 | |
| Metol | 1.0g | 3.0g | 3.0g | -- |
| Phenidone | -- | -- | -- | 0.5g |
| hydroquinone | 3.0g | 12.0g | 12.0g | 12.0g |
| sodium carbonate, monohydrated | 30.0g | 80.0g | 65.0g | 60.0g |
| sodium sulfite, anhydrous | 13.0g | 45.0g | 44.0g | 50.0g |
| potassium bromide | 1.0g | 2.0g | 2.0g | 2.0g |
| benzotriazole | -- | -- | -- | 0.2g |
| water to make | 1.0 liger | 1.0 liger | 1.0 liger | 1.0 liger |
| min dilution | stock | 1+1 | 1+2 | 1+1 |
| max dilution | stock | 1+4(*1) | 1+4 | 1+3 |
| dev. time | 1-2 min | 1-2 min | 1-3 min | 0.75 to 2 min |
(*1) For warmer tones on Kodabromide, dilute D-72 1+3 or 1+4 and 0.8g potassium bromide should be added to each liter of the diluted developer, and develop for 1.5 minutes.
As you might have noticed, the high degree of similarity among them suggests that these developers work quite similarly, and any of them is an excellent choice for today's standard print developer. One possible modification is to replace hydroquinone with ascorbic acid. Such a replacement is sometimes advantageous because of low toxicity, lower environmental impact and ease of preparation. One more disadvantage of hydroquinone is that, when hydroquinone developer is exhausted, the bath gives off quite unplesant odor. This is much reduced with ascorbic acid formula. DS-14 formula listed in the next section is a low-toxicity Dimezone-ascorbate print developer with excellent image quality with both old and modern printing emulsions.
In contrast to standard neutral tone developers, warm tone developers vary across manufacturers. This is in part because each formula is recommended for specific paper stock, and the emulsion used varies. The range of approaches used to obtain warmer image hue is quite large.
| Warmtone print developers | ||||
|---|---|---|---|---|
| AGFA 120 | AGFA 123 | GAF 135 | Ilford ID-78 | |
| Metol | -- | -- | 1.6g | -- |
| Phenidone | -- | -- | -- | 0.5g |
| hydroquinone | 24.0g | 24.0g | 6.6g | 12.0g |
| sodium carbonate, monohydrated | -- | -- | 24.0g | 62.0g |
| potassium carbonate | 80.0g | 80.0g | -- | -- |
| sodium sulfite, anhydrous | 60.0g | 24.0g | 24.0g | 50.0g |
| potassium bromide | -- | 25.0g | 2.8g (*1) | 0.4g |
| water to make | 1.0 liger | 1.0 liger | 1.0 liger | 1.0 liger |
| min dilution | 1+4 | 1+1 | 1+1 | 1+1 |
| max dilution | 1+5 | 1+4 | 1+3 | 1+3 |
| dev. time | 3-5 min | 2-6 min | 1.5+ min | 1 to 2 min |
AGFA 120 requires up to 50% increase exposure time compared to AGFA 100. AGFA 123 requires up to 150% increase exposure time compared to AGFA 100. Using Portriga Rapid (note: long discontinued, but this is a popular standard warmtone paper of the time), AGFA 120 1+4 produces brown black hue, while AGFA 123 produces neutral to sepia brown.
(*1) To increase the warmth, add bromide up to double the amount in the formula. The quantity of bromide specified in the formula, however, assures rich, warm, well-balanced tones.
Ilford ID-78 is for Ilford Kenprint paper and contact lantern plates.
AGFA 120 and 123 take most radical approach in omitting an effective electron transfer agent, such as Metol or Phenidone. This type of developers are still useful with Fortezo paper stock, producing orange brown hue. However, with increased bromide proportion in today's enlarging paper, these hydroquinone-only developers take very long time to develop, and the obtained hue may not be very drastic.
GAF 135 make more moderate departure from neutral tone developer. The amounts of metol, sulfite and carbonate are decreased. With this formula, the lower metol content, higher bromide content and lower pH work together to produce warmer hue.
Ilford ID-78 is almost identical to ID-62 except benzotriazole is omitted. However, the warmtone effect of this developer is most likely due to the formulation of the paper stock specified.
For classic warmtone paper stock still available today (such as Fortezo), any of AGFA 120, 123 or GAF 135 is still a good choice for warmtone developer. Also, these developers can be diluted for slow working to gain some control with graded paper stocks. This type of print developers are most useful with homemade print emulsions, where old fashioned chloride contact print emulsions and chlorobromide enlarging emulsions can be revived.
Again, one possible modification for these developers is to substitute hydroquinone with ascorbic acid. However, this type of substitution is not very effective in formulae like AGFA 120 and 123, because ascorbate itself is a very slowly working developing agent (much slower than hydroquinone).
For toning
When prints are toned for creative control, the print developer should be optimized for maximum toning effect. This can be done by maximizing the surface area-to-volume ratio of the developed grains. This can be done by optimizing the developing agents, pH, bromide level, sulfite, and processing temperature. For this goal, DS-14 (formula given below) was designed to maximize the toning effect as above, by selecting suitable values with many test printing sessions.
Although warmtone paper and warmtone print developer are used to make warm-toned prints without toning, warmtone developers are usually a poor choice for toning. The image often loses deep shadows if warmtone developer and toning process are combined. The image also may give suboptimal degree of toning effect, such as hue shift.
When prints are toned for permanence, hue shift is sometimes undesired. Neutral tone developer containing phenidone and benzotriazole, such as Ilford ID-62, tends to produce a print that minimally shifts its hue in selenium or polysulfide toning. This is particularly so in combination with neutral or cold tone paper stock.
Recommended developers
Two developer formulae are listed below. Factors discussed in above comparative study are all incorporated in these formulae to ensure excellent results. Another important feature of these two formulae is that they do not use hydroquinone. Hydroquinone is a very common developing agent but it has proven toxicity to laboratory animals (although existing data on human toxicity is somewhat mixed), fishes and other aquatic life. The recommended formulae below replace hydroquinone with ascorbic acid (vitamin C) which also has excellent developing property.
I recommend one neutral tone standard print developer, and one slow working warm tone print developer.
| DS-14, DS-15 print developers | ||
|---|---|---|
| DS-14 | DS-15 | |
| Metol | -- | 0.5g |
| Dimezone S | 0.2g | -- |
| ascorbic acid | 6.0g | 4.0g |
| sodium sulfite, anhydrous | 12.0g | 5.0g |
| sodium carbonate, monohydrate | 30.0g | 8.0g |
| triethanolamine, 99% | 5.0ml | 2.0ml |
| salicylic acid | 0.5g | 0.2g |
| potassium bromide | 1.0g | 3.0g |
| water to make | 1.0 liter | 1.0 liter |
| target pH | 10.4 ± 0.2 | 10.0 ± 0.2 |
Both developers are specified for use without dilution. If desired, 5 times the amount specified for each ingredients can be dissolved in one liter of water, and this stock solution may be diluted 1+4 immediately before use.
DS-14 is an excellent standard print developer. It is a modern formulation using safer alternatives to hydroquinone, and it performs like classic standard print developers. This developer is recommended for users who use Kodak Dektol, Kodak D-72, AGFA Neutol Plus (discontinued), Ilford Multigrade Developer, and other standard print developers.
DS-14 is suitable for processing in tray, tank and Nova slot processors, and standard developing time is 1.5 to 2 minutes. DS-14 can be replenished by top-off method. Use DS-14 itself, minus potassium bromide, as the replenisher. If colder tone is desired, 0.05g to 0.3g benzotriazole can be added to DS-14.
DS-15 is suitable for tray processing, and processing time varies with paper stock. The bromide in DS-15 can be increased or decreased for desired result.
In DS-14, Dimezone S may be substituted with Dimezone, Phenidone B, or Phenidone in decreasing order of desirability. However, preparation of concentrate may face solubility challange with Dimezone or Phenidone B. Phenidone or Phenidone A provides equal image quality, but with inferior solution keeping property. One work-around is to prepare the concentrate with any of these Phenidone derivatives, and add Phenidone or Dimezone immediately before use.
Commercial Availability
In 2006, two print developers, named Silvergrain Tektol Standard and Silvergrain Tektol Neutral became commercially available. They are improved versions of DS-14 developer above, incorporating some of my latest findings. Tektol Standard is the closer of the two to DS-14. Tektol Standard is highly concentrated (standard dilution 1+9; economy dilution 1+14) for convenience, and it also uses other improvements for image quality and keeping properties. Tektol Neutral is a coldtone version of Tektol Standard. The resulting image hue can be varied by blending Tektol Standard and Tektol Neutral.
Current users of Kodak Dektol and similar print developers will find Tektol Standard to work very similarly, but with the convenience of liquid concentrate stock and lower toxicity.
The formulae for commercial versions will remain proprietary as long as they are commercially offered for sale. (Sorry!)
Silvergrain Tektol print developers, as well as Clearfix Alkaline fixer and Clearwash washing aid are manufactured by an industrial chemical plant with strict quality control and sold by Digitaltruth Photo Ltd.
For more product info, pricing, MSDS, and other inquiries, please visit Digitaltruth Storefront. (The author of this page merely licenses the formula to Digitaltruth Photo and he does not handle sales, marketing, distribution or customer support.)
For those who prefer warmtone developers (for untoned prints), Digitaltruth sells a developer called Print-So-Fine. AGFA also sold Neutol WA, which is now discontinued. Most of these warmtone developers use hydroquinone.
