Fotospeed DY15 Fotodyes are designed to be used on any photographic emulsion. As true dyes, they are completely absorbed by the emulsion leaving no surface marking. The dyes come in 11 different colours with one reducer . All the dyes can be fully intermixed and /or diluted to produce any color or shade required. The dyes are extremely concentrated and caution should initially be exercised when diluting for use. It is very rare to use the dye undiluted except to color 35mm title slides. When using for the first time, we suggest you test the strength of colour on scrap prints. As a first test use 3 drops of dye to 1 teaspoon of water. You can then see the effect of stronger color by adding more drops of dye.