search  current discussion  categories  forms - tiles 

warped tiles - sandwich

updated wed 3 jul 02


Alistair Gillies on tue 2 jul 02

In message ,
Wanda Holmes writes
>Alister, please do describe in detail. Wanda

I will try.

I have in front of me about a quarter of a 6 inch [I think] tile. The
decoration on the tile is encaustic and the stylised plant motif must
have been stamped by a machine or at least a metal stamp as it is far
too fine to be hand produced or by plaster/bisque mold, some lines being
less than 1 mm wide. The top is also absolutely flat - it seems to have
been ground at some point. The depth of the encaustic pattern is a
fairly constant 1mm.
The majority of the pattern is the inlaid white clay leaving a line
drawing made from the top body layer. This is all covered with a
translucent blue glaze.
The precision of the top is in contrast to the composition of the tile.

Looking at a broken edge I can see a sandwich of clays with the outside
layers both being the same very fine, dark body [brown] enclosing a
lighter terracotta clay which contains large amounts of grog and other
impurities. These clays were plastic when assembled as the lines on
which they join are positively wavy.
Presumably the centre clay had the function of absorbing the tension
between the top and bottom layers both trying to warp, as well as,
possibly meaning that two thirds of the tile was made from a cheap
unrefined material.

The outside layers are 5mm widest and 3mm thinnest. The centre layer
varies from 10 to 12mm and the overall depth of the tile is 19mm.

On the back of the tile are numerous conical holes which go in at least
to the middle of the centre layer which would aid drying - the deepest
and therefore widest are 6mm at the bottom surface. These holes further
demonstrate that it was plastic clay as the bottom layer has been pushed
and stretched up into the middle layer getting thinner and thinner.


AGP Studio
01952 882909
07973 866198 [The builders are still working]