MuirMcNeil Triode is a geometric type system drawn in two forms, a solid version composed solely from straight lines and an alternate set composed solely from round dots. Each is drawn in seven weights based on the grid framework of the MuirMcNeil Two System. All Triode character bodies share common widths and spaces so that different styles or weights can be superimposed in multiple layers, although they are not fully compatible with the earlier design.

Triode explores the ways in which form and counterform can be constructed reciprocally, using a rhythmic structure of visual components at the baseline and x-height of almost all characters. Following similar principles to those of several other MuirMcNeil type designs, these patterns contribute to the composition of word shapes that are highly ambiguous but that attempt to remain as recognisable and readable as the constraints will allow. The result is a type system that is structurally incomplete but that maintains a good degree of integrity and legibility.