|Most tartans are symmetrical, and by showing them in a colour
disk, we can easily compare tartan patterns, A colour disk "normalises"
any pattern, ignoring how many threads are in the pattern, and
allowing patterns to be compared. In a sense, the colour scheme
can also be ignored and it is just the contrasting bands within
the pattern that emerge.|
Apart from the more obvious varieties of Stewart tartan, a
great number of other famous tartans employ a similar pattern.
Drummond above reduces to the disk on its left. By using
two shades of blue around the white line, a misty effect results.
The green has expanded to become the secondary under check and
the yellow and white that over check the now absent black, are
thinned to guard the blue band.
The Racing Stewart illustrates how the basic pattern may be
altered from Royal Stewart: the blue is lightened and expanded
to replace the large red under check. Blue is then "replaced"
by white, as is yellow, and the green has been lightened. The
remaining red under check is simplified by removing the black
The result for Racing Stewart is a simpler design, using light
blue and green to highlight a simpler red feature, and the white
and black support the distinctive Royal Stewart effect.
However, it was probably Stewart Black and not Royal Stewart
that was the basis of Racing Stewart: The blue has invaded the
large black region and pushed the remaining pattern into the
lower hemisphere of the Tartan Colour Disk.