5. Conclusion

The work is aimed to create an approach to the ideal colorants definition and calculation. We assume the existing of the relationship between two device-dependent color spaces (CMYK and RGB) accounting the color quantization in print (as for instance, in electrophotography). This makes the systems to be able to precisely express primaries of additive color synthesis (R, G, B) as binaries of subtractive color synthesis colorants (C, M, Y). For this, the universal CIE Labcolor space is used in computations. The binary surface is defined as a gradation surface of two colorants that is “stretched” on their gradation trajectories.
An ideal colorant is such a combination (mixture) of the initial colorants, which ensures the minimal fluctuations of color tone (i.e. color difference) in a range from an unprinted substrate to a full dye. The gradation trajectory of the ideal colorant is the geodesic on the gradation surface of two adjacent initial colorants. The trajectory satisfies the condition of the minimum possible color difference between the color quanta that form it. A discrete interpretation of the ideal colorant computation is proposed in terms of gradation trajectories in the CIE Lab space together with the color quanta as an expression of color quantization.
In the case of electrophotography, the practical implementation of the ideal printed colorant will require a complete revision of the model of subtractive color synthesis, which is hardly in the interests of production. However, this question is extremely interesting from a theoretical point of view. The case of inkjet printing, also, requires particular consideration.