The selection of a solvent is based on several factors, including flammability, cost, ease of preparation, and the potential destruction of handwriting evidence. The last factor may be the most significant, because many solvents will liquify or dissolve writing inks. Freon has been extensively used to avoid damaging writing inks, but the environmental destruction caused by freon and other CFC's has already limited their availability. The production of Freon 113, the most commonly used CFC in freon/ninhydrin processing, will soon cease. Efforts to find an alternative led to experiments with heptane, which did not damage most writing inks but also did not dissolve ninhydrin. Continued experiments at both the Naval Criminal Investigative Service in Norfolk and the Internal Revenue Service laboratories have created different modifications to the original formulas. In repeated tests and under diverse climates, visualized latent prints developed with heptane/ninhydrin were equal or better in clarify and intensity to those developed with other solvent reagents. Descriptions of preparations and procedures used and address from which to obtain further information