1. The monumental canopy with figures in front of it.
2. Strong contrast of light and shade.
3. Fairly accurate perspective in the architecture.
4. Something like atmospheric effect in the landscape, which is painted more or less upon the sky.
When in a canopy the shadowed portions of the architecture are glazed in deep-coloured glass (purple, as a rule), and not darkened by painting, it indicates the early part of the century. The canopy, instead of being arched, ends sometimes in a rich frieze and cornice (Church of Brou). When it is in two stages, enclosing two subjects, the lower one has naturally this horizontal entablature (Chapel of the Holy Sacrament, S. Gudule).
A less usual treatment is where the figures do not occupy the foreground, but are seen through the arch. The subject occupies, in fact, very much the position of a painted altar-piece in a carved stone altar.
Foreground figures prove often to be donors and their patron saints. The head of the window above the great architectural canopy, as it is convenient to call it, is usually of plain white glass, glazed in rectangular or diamond quarries ([page 71]).
A coloured ground above a Renaissance canopy indicates Gothic tradition, and an Early period therefore (S. Jacques, Liège).
More to the latter half of the century belong the pictorial compositions in which architecture, more or less proper to the subject, fills great part of the window, the foremost arches adapting themselves, sometimes, to the stonework. In this case the architecture is in white glass, more or less obscured by painted shadow; and pot-metal colour occurs only in the figures, where it is perhaps quite rich, in occasional columns of coloured marble, and in a peep of pale blue distance seen through some window or other opening ([page 213]).