Photographers' Formulary 03-0150 Residual Hypo Test for Darkroom Used to test whether film or prints have been adequately washed. Easy to read results Economical to use Photographers' Formulary Residual Hypo Test is a simple chemical test that can be used to determine if a print or film strip has been adequately washed. The test will give accurate results if the print or film has been treated with hypo clearing agent and washed in water or just washed in water This test is reliable when used on either fiber or RC papers The chemicals in this kit are mixed and ready-to-use with no further dilution needed