with classic mouldings represented
in colour, surrounding radiating green and blue leaves;[25] some more
strictly classical are not unlike Italian patterns; some again are more
naturalistic, while in others the pattern, though not of the old
geometric form, is still Moorish in design.

Together with the older tiles of Moorish pattern plain tiles were often
made in which each separate tile, usually square, but at times
rhomboidal or oblong, was of one colour, and such tiles were often used
from quite early times down at least to the end of the seventeenth
century.

More restricted in use were the beautiful embossed tiles found in the
palace at Cintra, in which each has on it a raised green vine-leaf and
tendril, or more rarely a dark bunch of grapes.

Towards the middle of the sixteenth century the Moorish technique of
tilemaking, with its patterns marked off by raised edges, began to go
out of fashion, and instead the patterns were outlined in dark blue and
painted on to flat tiles. About the same time large pictures painted on
tiles came into use, at first, as in the work of Francisco de Mattos,
with scenes more or less in their natural colours, and later in the
second half of the seventeenth century, and in the beginning of the
eighteenth in blue on a white ground.

Towards the end of the eighteenth century blue seems to have usurped the
place of all other colours, and from that time, especially in or near
Oporto, tiles were used to mask all the exterior rubble walls of houses
and churches, even spires or bulbous domes being sometimes so covered.

Now in Oporto nearly all the houses are so covered, usually with
blue-and-white tiles, though on the more modern they may be embossed and
pale green or yellow, sometimes even brown. But all the tiles from the
beginning of the nineteenth century to the present day are marked by the
poverty of the colour and of the pattern, and still more by the hard
shiny glaze, which may be technically more perfect, but is infinitely
inferior in beauty to the duller and softer glaze of the previous
centuries.

When square tiles were used they were throughout singularly uniform in
size, being a little below or a little above five inches square. The
ground is always white with a slightly blueish tinge. In the earlier
tiles of Arab pattern the colours are blue, green, and brown; very
rarely, and that in some of the oldest tiles, the pattern may be in
black; yellow is scarcely ever seen.