Crone-C Additive converts D-76 to C-76 by the addition of one ounce of additive to a liter of D-76. The boost given by Crone-C Additive improves shadow detail, even with the recommended shorter development. The shorter development time helps to limit grain growth. It preserves sharpness and protects you film and still give easy to print negatives. Shelf life is 1 year in a tightly sealed bottle. Supplied as liquid concentrate.