The Journal of Australian Ceramics Vol 49 No 3 November 2010

Technical: Mosaic
WOlklng on the panels at the Butter Faaory Ans Centre workshop; photo: Jennifer Sadler
The Making Process
This approach to mosaic is entirely different to the style of mosaic where small tesserae are used to
build up the design. Cutting the design into soft clay has great appeal as a contrast to working with
hammers and tile nippers. I enjoy both techniques and they can be combined to great effect. Careful
consideration must be given to break up the design into workable segments. This influences the design
itself. Shrinkage of the clay during drying and firing automatically creates grout spaces. We also allowed
for 10% shrinkage. Backing boards were not cut until all tiles had been fired.
The full size design was drawn up onto clear plastic with a permanent marker, using metho to wipe
off any mistakes. Clay was rolled to about 1 cm and left to rest before cutting. Working with 'soft
leather hard' clay gave the best results. The design was transferred through the plastic by scribing with a
pencil or ballpoint pen . Tiles were cut out and numbered to match the design - this was very important
because the tiles are handled and moved many times, especially in a group situation!
Tiles can be textured, incised and stamped using natural and man-made materials. In this project
an old farm fencepost was used to create tree textures. One group member supplied a remnant of
her wedding dress lace to texture the mountain. (This created a beautiful link to the grandma story.)
Relief areas were built up in some places. The tiles were dried very slowly between boards to eliminate
warping.
Walkers BRS (Buff Raku with Sand) was used for this project, with white earthenware decorating slip
applied to some areas. Text elements were hand painted onto individual tiles using black underglaze.
Tiles were bisque-fired to 1000°C. Oxide washes were used in various combinations to produce an
earthy palette of colours and Deco underglaze colours were also used in some areas. Mal made a
'mystery' metallic glaze for the saw blades and axe head. A brush-on clear mid-fire glaze was then
applied and all tiles were fired to 1200°C.
Backing boards were cut from 6 mm compressed fibre cement sheeting sealed on both sides with
S4 THE JOURNAL OF AUSTRALIAN CERAMICS NOVEMBER 2010