|
Tennessee
Tech
University
- Appalachian Center for Craft - Clay Studio
Vince Pitelka, 2007
Art
3520 - Advanced Clay Studio - Surface Design
Decorating Slip Consistency Based on Water Content
Material consistency in decorating slips determined by water content is critical
in any slip-decorating technique, as the surface effects will change
dramatically as slip consistency changes. Some
decorating techniques are possible only with thick slips, others with medium or
thin slips. The following chart is
based on the performance of our standard flocculated decorating slip (and does
not apply to deflocculated slips or to terra sigillata and other
particle-refined slips). Amounts are
given for 100-gram samples of dry base slip in order to simplify the task of
multiplying the recipe for your particular needs.
The second column indicates the amount of water added, the third
indicates the percentage of water added to the dry batch (% of the dry batch
weight), and the fourth the percentage water in the mixed batch.
In each case, approximate characteristics and possible uses are given at
the right.
|
Slip
Consistency Chart
|
|
Dry
Mix
|
Water
|
%
of Dry
|
%
of Total
|
Slip Characteristics and Uses
|
|
100 g.
|
40 ml.
|
40
|
28.5
|
Very soft claybody - modeling,
texturing
|
|
100 g.
|
50 ml.
|
50
|
33.3
|
Stiff paste - modeling, texturing with
palette knife
|
|
100 g.
|
60 ml.
|
60
|
37.5
|
Paste/slurry - textural painting,
texturing with brush or palette knife
|
|
100 g.
|
70 ml.
|
70
|
41.2
|
Medium slurry - textural painting,
stippling, layering, sgraffito, thick trailing, tube-lining, texturing
|
|
100 g.
|
80 ml.
|
80
|
44.4
|
Thin slurry - textural painting,
stippling, layering, sgraffito, thick/medium trailing, tube-lining
|
|
100 g.
|
90 ml.
|
90
|
47.4
|
Thin slurry - painting, sgraffito,
medium trailing
|
|
100 g.
|
100 ml.
|
100
|
50.0
|
Barely pourable - painting, sgraffito,
medium/thin trailing
|
|
100 g.
|
120 ml.
|
120
|
54.5
|
*Pourable - thin painting, sgraffito,
thin trailing, marbling, feather combing
|
|
100 g.
|
140 ml.
|
140
|
58.3
|
Liquid - very thin painting
|
|
100 g.
|
160 ml.
|
160
|
61.5
|
Very liquid - translucent patina/wash
effect
|
* Might require slight adjustment of water content for techniques that require
separate colored slips to intermingle without intermixing, as in feather combing
and marbling. For those effects, the
slip must be liquid enough so that it will seek its own level in its container
after it is disturbed. In other
words, when you draw a brush through the surface of the slip in the container,
the slip should return to completely level, leaving no raised “wake.”
Add water very slowly to reach this point, because you don’t want to
thin the slip any more than this for these techniques.
|
