Magic Lith Prototype Update #3

No pictures this time because the results have been pretty boring. Basically, I’ve found that a magic lith formulation can be a lot more flexible than expected, with the primary requirement being a relatively high amount of hydroquinone and a relatively high pH. I’ve done some tests with alkaline prebaths. This seems to help the evenness of a print significantly, but comes with it’s own problems. The print can’t be rinsed after the prebath or else it returns to hardened form and will develop unevely. If the prebath is too alkaline and/or soaked for too long, the print will have a mottle-like effect, but will develop evenly otherwise and quite quickly with the low contrast image appearing rather quickly and then infectious development occurring throughout the print. If done properly the print can also be pulled more quickly and thus with more color. Thus far my best results have been with 2.5m with 1.5L of water + 15ml of 3% hydroxide.

I’ve changed to using a larger tray and 2L of developer at a time which seems to help the evenness as well as tray life but is not a complete solution.

Benzotriazole is an essential component in this developer. Without it, you will get both peppering and yellow staining on the border. With ~5ml/L both will go away. Too much seems to make the uneven development problem worse though.

Bromide is not as terrible as expected. I don’t really understand, but it has more effect in a carbonate based developer than a hydroxide developer, even if both are around the same pH. Iodide is optional.. I can’t really see a huge effect when it is present with bromide, even with a large amount of iodide. With very small or no bromide it does work as a restrainer of sorts, but not a good one.

HQ amount is still a bit of a mystery. More HQ will produce better blacks, but also cause more overall development. High amounts of HQ will produce some fogging with long development times and thus if higher contrast is desired, then going close to the normal print time (rather than massive over exposing) will produce a low contrast image which will then be affected by infectious development to produce proper blacks and darkening of low mid tones.