"Of all the discoveries I have made, NONE were the result of rational thought." - Albert Einstein In "wringing out" Arista Premium 400 I noticed a bottle of developer I had used, opened in the year 2001; Alta's Zonal Pro Gamma Plus. On a sheer whim... I had trouble in opening the bottle ... I mixed it 1:20 and developed the Tri -- oops ... Arista for 13 minutes @ 20 C in the JOBO. The results were fabulous! Beautiful tonal scale, contrast.... an aesthetically pleasing (to me) grain structure - all from what might have been oxidized developer (note: Eight (8) years!). Does this stuff improve over time, like wine?!? ... And the film was exposed a box speed - ISO 400. In any event, Gamma Plus will see much more use. Anyone else have experience/ knowledge of what "type" of developer - anything else about Gamma+ ?