Cold-rolling and vacuum evaporation techniques supplemented by die compaction, electroplating, and painting, can be used to prepare a complete range of stable isotope targets with thicknesses varying from a few micrograms per square centimeter to several grams per square centimeter. Techniques used at Harwell to prepare radioactive targets are vacuum sublimation, electrospraying, molecular plating, electrodeposition, and painting. Of these, the two most reliable processes are vacuum sublimation, for preparing thin “weightsless” sources, and painting, for preparing thick adherent sources.