![]() The price is 20¢/gram, or $200/kg, plus shipping & packaging (email me for an estimate). Many others here on APUG have done a lot of digging, reading and experimenting to pave the way for this group buy many thanks to them too! (you know who you are ) (there was a url link here which no longer exists) has been the clearing house for most of this information. A great debt is owed to Tod and Charles Berger for sharing their experience with this sensitizer amongst the carbon community. Tod Gangler personally tested this batch of sensitizer and gave it his approval. DAS is sensitive to UV light just like the dichromates (its sensitivity peak is 335nm). I believe that printing times are generally a bit longer however. Contrast is affected by changes in sensitizer concentration, just like dichromates. For 500mL of pigmented gelatin, that's only 3 grams of sensitizer. Detailed information about the sensitizer will be included with all orders.Īs an incorporated sensitizer it's recommended to use DAS at 0.6% as a starting point. With refrigeration it will keep well, even better with freezing (the manufacturer has kept this stock frozen since 2006 and its properties have not changed). Also, the sensitizer powder should be refrigerated and kept away from light. The manner in which the sensitizer is incorporated into pigmented gelatin or "glop" is elucidated (there was a url link here which no longer exists), and there is a simple clearing bath ((there was a url link here which no longer exists)) which uses a minute amount of potassium permanganate. who knows.ĭifferences in working technique with DAS are minimal. ![]() Refrigerated tissues should keep well for several years and frozen tissues. UltraStable tissues from the mid-90's will still make prints today.Īlthough I can't give any hard facts or guarantees at the moment, all the information we've been seeing tells us that pre-sensitized tissues should keep on the scale of years, depending on humidity and temperature. What this means it that tissues can be made with incorporated sensitizer (pre-sensitized) and they will keep for long periods of time. In addition to being environmentally friendly and safe to work with, it has no "dark reaction" like the dichromates. This sensitizer is a non-carcinogenic and non-toxic alternative to the dichromates historically used in carbon printing (potassium, ammonium, etc.) and similar processes ((there was a url link here which no longer exists), PVA, probably more). If you're not familiar with 4,4'-Diazidostilbene-2,2'-disulfonic acid, disodium salt, tetrahydrate, it's much easier to call it DAS, or the amazing azide sensitizer that was used in the UltraStable process and which is currently being used by the world's leading color-carbon printer, Tod Gangler.
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