Abstract: The present invention relates to electrophotography, and in particular to the formation of a permanent image in one or more colors from latent electrostatic images which correspond to the color separations of an original and the developing of which is effected by means of a developer composed of polymer particles containing at least one dyestuff which can sublime or vaporize at between 100.degree. and 250.degree. C. The recording is effected under dry conditions by vaporization or sublimation of the dyestuffs present in the developers, without any fixing operation following the transfer of the dyestuffs onto the support which receives the recording.

Abstract: Dry developer for the development of electrophotographic latent images, consisting of a single type of very fine particle containing an electrically conductive substance, a magnetic substance and a binder, characterized in that it has a high conductivity, greater than 10.sup.-2 Siemens cm, and in that this conductivity is independent of the value of the electrical field applied and its use in a process for development of electrophotographic latent images wherein it is applied from an insulating surface.

Abstract: An electrophotographic developer is composed of particles comprising magnetic cores which are coated with an organic substance and at least one dyestuff which passes into the vapour state at a temperature in the range of from 100.degree. to 220.degree. C. at atmospheric pressure.

Abstract: The invention provides an improvement in the known dry thermoprinting process making it possible to employ the process to dye or print natural fibers or mixtures of natural and synthetic fibers. Textile material consisting of natural fibers or of a mixture of natural and synthetic fibers is impregnated with a precondensate of a thermosetting resin. The thus impregnated material is then dyed or printed by the dry thermoprinting process, the curing of the resin taking place during the transfer of the dyestuff.

Abstract: Temporary carriers which can be used in the thermoprinting technique, and particularly in thermoprinting textiles by transfer, characterized in that they comprise a print which is generally multicolored and which is produced from an alkalizing agent and one or more cationic dyestuffs, which, at atmospheric pressure, pass into the vapor state at temperature above 160.degree. C, the said print being carried by a sheet or strip of sulphurized paper.

Abstract: The invention relates to a dyestuff preparation containing1. at least one dyestuff and/or fluorescent brightening agent which sublimes at 100.degree. to 300.degree.C and2. at least one resin soluble in organic solvents.