Cloth is woven by threads at right angles to each other and, using a set
of coloured threads in the same order, these combine to create a tartan
Tartans are therefore woven on long coloured threads called the warp
and the same pattern is then crossed through the warp threads, thread
by thread, to form the weft, the weft threads passing twice from side
to side back to the same edge of the cloth called the selvedge.
The thread count is repeated in one of two ways. If repeated in reverse
order, the tartan becomes symmetrical. If repeated from the beginning,
then it becomes asymmetrical.
|The Robertson pattern below is symmetrical whilst the Hebridean
pattern is asymmetrical. In the Robertson the green tramline
marks the end of the threadcount, which then goes into reverse. In the Hebridean,
the dark stripe at the end of the count is followed by the green again.
Whatever form of repetition, the tartan's pivots are the beginning and
the end of the thread count but in an asymmetrical tartan, there is just
To locate the pivots, find a diagonal of squares that are all pure colour.
Most tartans are symmetrical and the warp and weft cross to make these pure
colours: the thread count becomes these boxes of colour in two dimensions.
In some patterns, there are isolated squares where the same colour is used
in different parts of the count but usually these are not square but rectangular.
The Borthwick Tartan below shows a clear diagonal from top left to the magenta
Having found a main diagonal, the pivots will be at the
centre of two of them. Often these pivot under
checks are embellished with an over
check to pinpoint the pivot. In the Borthwick Tartan the pivots are
visible as green and magenta "crosses".To find the pivots therefore, try to locate a diagonal made up of pure colour
squares. Work out if the pattern reverses, is symmetrical,
or starts again. Then identify the under checks, two of which hold the