what it does,
just because it would be a gross vulgarity to use it where it would
pretend to be a diamond?

The safe guide (as far as there can be a _guide_ where I have maintained
that there should not be a _rule_) is, surely, to generally get the
depth of colour that you want by the glass itself, _if you can_, and
therefore with that aim to deal with rich, full-coloured glass and to
promote its manufacture. But this being once done and the resource
carried to its full limit, there is no reason why you should deny
yourself the further resource of touching it with pigment to any extent
that may seem fit to you as an artist, and necessary to get the effect
of colour and texture that you are aiming at, in the thing seen as a
whole. As to the exaggeration of making accidental streaks in the glass
do duty for folds of drapery, and manufacturing glass (as has been done)
to meet this purpose, I hold the thing to be a gross degradation and an
entire misconception of the relation of materials to art. You may also
lay this to mind, as a thing worthy of consideration, that all old glass
was painted, and that no school of stained-glass has ever existed which
made a principle of refusing this aid. I would never argue from this that
such cannot exist, but it is a thing to be thought on.

Throw your net, then, into every sea, and catch what you can. Learn what
purple is, in the north ambulatory at York; what green is, in the east
window of the same, in the ante-chapel of New College, Oxford, and in
the "Adam and Eve" window in the north aisle at Fairford; what blue and
red are, in the glorious east window of the nave at Gloucester, and in
the glow and gloom of Chartres and Canterbury and King's College,
Cambridge. And when you have got all these things in your mind, and
gathered lavishly in the field of Nature also, face your problem with a
heart heated through with the memory of them all, and with a will braced
as to a great and arduous task, but one of rich reward. For remember
this (and so let us draw to an end), that in any large window the spaces
are so great and the problems so numerous that a _few_ colours and
groupings of colour, however well chosen, will not suffice. Set out the
main scheme of colours first: those that shall lead and preponderate and
convey your meaning to the mind and your intended impression to the eye.
But if you stop here, the effect will be hard and coarse and
cold-hearted in its harmonies, a lot of b