Ilford offers nuclear emulsions with either 0.2µm (K) or 0.11µm (L) crystal diameters, depending on the viewing system and activity of the isotope used. L4 emulsion is recommended for electron microscopy, as it has the highest resolution, and K series emulsions are more suited to light microscopy applications.
When using H3 or I125 either K2 or K5 emulsion may be used. K2 emulsion offers a lower background, whereas K5 allows shorter exposure times to be used.
Emulsions must be stored at 4 - 5°C without freezing, since they deteriorate at temperatures appreciably above this. For this reason, these emulsions are not normally stocked, but can be obtained on request.