earlk on tue 9 may 06
If I go to the hardware store and read the
labels on a can of paint they will make a
big deal of the "Covering Power" of their
product. Generally, I take this to mean
the ability of the paint to hide whatever
color is being painted over.
It seems to me that the same concept
can be applied to a glaze; i.e. how well
does it hide the color of the ceramic
body of the pot. A transparent glaze
would have, essentially, zero covering
power whereas a glaze loaded with
Zircopax or tin might have a covering
power of 100.
I find it interesting that this attribute of
a glaze is seldom mentioned, at least in
these terms, when people discuss a
glaze recipie.
Other than the zirconium opacifiers, tin,
titanium dioxide, gas bubbles and crystal
growth what other factors would affect
the covering power of a glaze?
Just something else to cogitate.
earlk...
bothell, wa, usa
Daniel Semler on wed 10 may 06
Hi Earl,
Thickness would be a factor I would think. I don't know if that would matter
as much with paints, depending upon the expected surface preparation. But
particularly with a well developed glaze/body interface I would think
thickness
would be important. Depends a little on whether "covering power" is simply
talking about colour or whether they also include the ability to hide surface
texture to some extent.
> Other than the zirconium opacifiers, tin,
> titanium dioxide, gas bubbles and crystal
> growth what other factors would affect
> the covering power of a glaze?
Thanx
D
Daniel Semler on wed 10 may 06
Oh, also the body would be relevant. I would expect some glazes to
"cover" some
bodies very well and others not so well. Can "covering power" be defined
independently of the body the glaze is applied to ?
Thanx
D
May Luk on wed 10 may 06
How about un-dissolved or un-melted oxide?
May
Ivor and Olive Lewis on thu 11 may 06
Dear Earl k=20
You may have a point but take care that you are not comparing apples and =
cheese.
Covering power is usually expressed as square metres per litre or square =
feet per pint and is about how far the paint will stretch. If you wish =
to hide what is underneath then you are talking about Obscuring Power. =
No doubt in each case, with paint, dense titanium white will stretch a =
long way and obscure everything with one coat....if the background has a =
light tone. But if someone has being cartooning in broad black brush =
strokes, several coats may be needed.
But it is still a great concept.
Best regards,
Ivor
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