Re: gesso for watercolor?
thanks a lot, loris, for the great description there. i will definitely
try this.
the layout of the lascaux datasheet is a little confusing (sorry, should
have mentioned it), it has 4 products on two pages. the gesso is at the
bottom of the left column on page one. the descrption says: /"Pure
acrylic resin dispersion with rutile titanium dioxide and mineral based
extenders. a semi-absorbent primer for canvas, qualified for oil-,
acrylic, water- and tempera painting. it is a more absorbent variant of
Lascaux Primer"
/so, it's most likely just a variation of the primer with more marble
dust or something similar. i'd rather order some marble dust and use up
the rest of the primer i already have.
phritz
Loris Medici schrieb:
Phritz,
I don't think the "lascaux" gesso is much different than any other acrylic
gessoes you'll find in the market. It says "acrylic resin dispersion +
titanium dioxide + mineral based extenders", they're not mentioning any
other filler (usually calcium carbonate - to make it more absorbent) and
also they don't say "it's suitable for watercolor". (Only egg-tempera, oil
and acrylics are listed in the product sheet. I don't see the need / point
of using acrylic gesso for watercolor painting BTW; it's contradictory to
my understanting of the medium!) So, I don't think you'll have better
performance than other brands, unless you do "something" to make it
suitable for gum printing.
Try this: purchase the cheapest acrylic gesso you can get (I mean real
cheap here!), and mix some calcium carbonate powder (or marble dust) into
it, and apply this onto the surface (BTW, stick with good old gelatin if
your intention is to print on paper!) then size. That's it. I'm sure Keith
will provide more options and thoughts as I learned this from him -> he
has far more (superior) experience than I have.
My formula is as following:
a) 1 part acrylic gesso, b) 2 parts calcium carbonate powder, c) 2 parts
water (all by weight)
Put b into a, mix well (really well - thoroughly, as much as homogeneous
as it could get) then add c in small portions (still stirring, just like
making mayonnaise), filter throuth cheesecloth (if you feel it's too rough
and there are clumps), apply onto surface in thin and even coatings in
perpendicular order (using a brush or foam roller), drying each layer with
a hairdryer. You may want to sand between each layer or the last layer or
no sanding at all. Then size with 1.5% (or more depending on your
experience) hardened gelatin.
Fiddle with calcium carbonate amnt. (and sizing strenght) to increase /
decrease tooth / absorption, fiddle with water amount to find a
consistency you're comfortable to work with.
Regards,
Loris.
16 Mart 2009, Pazartesi, 9:14 pm tarihinde, Katharine Thayer yazmış:
...
Recently Keith Gerling and Loris Medici traded observations about
gesso in various combinations as a sub for gum on wood and on
aluminum ; you should be able to find that thread in the recent archives
http://www.usask.ca/lists/alt-photo-process-l/
or maybe they'll chime in to answer here.
Katharine
On Mar 16, 2009, at 9:48 AM, phritz phantom wrote:
is this stuff the same as acrylic gesso/primer?
i've used acrylic before and the results were ugly: flaking, very
greyish... allover not pleasant. at all dilutions.also sometimes
the emulsion seems to go very deep into the size, so the prints
could really take a strong brushing without the emulsion coming
off. mixing it with gelatine helped a little, but still not as
good as pure gelatin or no size at all.
now (i still have almost a whole bucket of acrylic gesso left...a
500ml was the smallest size) i've found out that acrylic primer is
not suited fot watercolor pigments. i should read labels before
buying. but i found a gesso which is suited for watercolor, it's
lascaux gesso. but before i spend money on half a liter of stuff
that doesn't work either, has anyone ever tried this product?
here's a link to the datasheet:
http://www.lascaux.ch/pdf/en/produkte/malhilfen/impraeg_grund/
52305.02_grundierungen_.pdf
phritz
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