Pseudo-components are transformed values of the components (plotted in Ternary graphs) where:

x'i = (xi-Li)/(Total-L)

Here, x'i stands for the ith pseudo-component, xi stands for the original component value, Li stands for the lower constraint (limit) for the ith component, L stands for the sum of all lower constraints (limits) for all components in the design, and Total stands for the mixture total. This transformation makes the coefficients for different factors comparable in size.

See Ternary Graphs (and Cornell, 1990a, Chapter 3); see also the discussion of mixture designs in Experimental Design.