From: =?iso-8859-1?Q?Mathieu_Ren=E9?= <creaturiste-AT-primus.ca>
To: <puptcrit-AT-puptcrit.org>
Date: Thu, 2 Oct 2008 22:13:38 -0400
Subject: [Puptcrit] Paper Strips Casting: super strong and detailed


Hi all.
Today I worked on the most detailed paper mache heads I ever casted in a 
plaster mold.
The definition is surprisingly high.
I had two molds. Each made in two parts, paper applied on the parts 
separately, the cast will be trimmed and attached later.

It went very fast too!
I had time to cast 8 layers on the first head mold, and 4 layers on the 
second, thanks to my fan, and alternating between each piece. I could have 
done more, but I also had to go shopping for supplies.

I was a bit worried for the nose on the first head (it's insanely small), so 
I pulled the face out of the mold after the third layer was firm enough. 
That's when I saw how well it went! Then I carefukly put it back into the 
mold.
I wish I could show you. It's a short film contract, so releasing pics is 
not good without authorisation. I'll work on it.

What made it so much better than before?
One forgetful moment and a change of glue.

This morning I forgot to bring some copy paper or other thin paper to use as 
a release layer in the mold (wet paper only, no glue). so I used what was 
around at the studio, which was Newsprint. Yikes! I've never had such a nice 
and stable application before! It's so soft it takes details well.

Then I changed glue, I used Exterior Carpenter's glue (brand is Lepage).
I recently commented about it, saying it was a bit more flexible than I 
liked, otherwise it was very strong. Well, this morning, I checkd my giant 
skull mask, and it was the ideal stiffness! I hadn't worked on it in a few 
days, so it had time to dry completely (it's hollow now).
I dilute it a bit with water, unbtil the glue can be brushed easily, gliding 
on the paper. It also makes the glue easily absorbable by the paper.

Each time I start a layer, I write the number corresponding to the layer I,m 
doing, on a dry pice of the paper I use, then I fglue it to the rim of my 
mold. No more forgetting how maby layers I did!

Each time I finish a layer, I place the mold in front of the fan, and work 
on another mold piece.



For the curious, the whole process:

Materials:
-negative plaster mold with limited undercuts (paper is flexible to a point)
-newsprint for the release layer
-coffee filters for the paper mache strips
-Exterior Caprenter's glue (I use Lepage), or a good quality white glue (not 
craft, and not School) will work
-water in a spray bottle
-bucket o' water
-hogs bristle brush
-Fan

1- make negative plaster mold, alowing about two incehss of rim around the 
form (place your walls accordingly). Avoid using any oily material inside 
the mold, but the edges can have some. Let cure and dry at least a few hours 
(otherwise it's brittle, you risk breakage of small details). Clean mold so 
that it has no greasy residues. DO NOT seal this kind of mold. We need the 
plaster to absorb moisture and speed our drying time.

2-tear a lot of small pieces of newsprint paper (newspaper might also work, 
it's almost the same thing).
Also tear a few very small pieces (qarter inch wide by an inch long for 
small details).

3- one by one, dip a piece of paper in water, lay it in the negative mold, 
pressing-tapping with a wet hogs bristle brush. Start from the sides, this 
will make you a good handle to pull of cast later, and it also prevent the 
model to warp inside the mold.

4-Once the sides are done, overlap the edge and get into the mold working 
your way around and down.
Smaller pieces for smaller details. Spray with water once in a while, to 
keep things moist (not dripping wet), so that the pieces will stay put.. 
Sometimes you'll need to repress with the wet brush.
This layre is important, make it as preceise as possible.

5-The glue coat. Very gently brush-dab a coat of the glue over the pices of 
wet paper. the glue must be the right consistency to stay atop the paper and 
not penetrate, while it should not be too sticky.
Some pieces of paper will pull off. be gentler, and lay a new piece iof wet 
paper atop the gap, trying to avcoid kletting any glue touch the plaster 
directly.
thios layer of glue will hold the release layer in place, but still allow 
some flexibility for the future layers to dig into details.

6-Let that glue layer dry on its own if time allows. Or place in front of a 
fan, low setting. Do not use heat at this point, this layer likes shrinking 
and warping, pullin away fromt he mold!

7- all the other layers are the usual paper mache strips, using the same 
glue as above.
The first and second layers are to be as prefect as possible. The rest can 
be applied more roughly, as long as the wrinkles aren't too dramatic. Make 
it smooth if you intedn to add mechanics into the puppet head, it will make 
the inner manipulations easier on the hands...

Preferably you should let each layer dry almost fully (looks dry, matte, not 
too cold to the touch, don't feel liquid underneath), but if you must add as 
much as you can all at once, us as little glue as possible (without making 
it too dry wither) limit yourself to 4 layers, otherwise it will take longer 
than the night (8 hours, in front of the fan) to dry.

8-When the cast is dry enough to manipulate without tearing, you can gently 
pul it inward, then out, slowly, following the form of the mold, until free. 
Reform the cast as best you can if it has warped while pulling. Tears can be 
repaired easily with more paper, but start from inside and use a thicker 
glue (the same but not diluted). When dry, use the diluted glue to repair 
the surface.

9- Lay the cast parts, opening down, on a grill or a screen, so that it will 
dry completely. Place in front of the fan, at low setting.

10 -When it is stiff enough to manipulate wihout warping, you should rub a 
layer of the diluted glue everywhere, to flatten the loose edges of the 
release layer. Try not to remove too much of the loose edges, they would 
leave gaps in your paper cast.  Rub with a smooth hard tool, to flatten 
everything very well. Let or make dry with a fan. You may trim it with 
scisors or precision knife, and assemble the parts together. As described 
for repairing tears, start from underneath with the pure glue and coffee 
filters, and when dry, do the surface with the diluted version and coffee 
filters.
>From this point on, using a heat gun or hair dryer is ok and a real 
timesaver, but keep the temperature low.

11-dry the head
Full cure (final stiffness could take 48 hours after it feels dry to the 
touch. however, the head can be trimmed further and even painted with 
acrylic paints, before it has fully cured, as long as it feels strong and 
stable. Make sure you use only acrylic paints if you don't wait for full 
cure, as this kind of paint keep breathing, even when it is dry, allowing 
for the moisture underneath to escape, even if a bit slowly.

12-Trimming. With scissors and/or craft knife. When trimming and cutting 
around and into paper mache strip projects, always re-seal the new edges 
with more of the same paper and glue. Two layers is a minimum, three or four 
is better. This will avoid fraying and warping.  I usually seal the outer 
edges of masks and bigger puppet heads after I have applied the border wire, 
which is used to strenghten the edge and guard the shape.

12- Seal the head. I prefer using diluted Weldbond, but a layer of pure, 
undiluted acrylic paint will do very well, if you really don't touch it 
until it's perfectly dry. This step prevents cracking (acrylic paints 
(diluted or cheap) crack if painted directly on white glue and carpenter's 
glue) and offer a great grabbing primer.
Avoid acrylic gesso for sealing this type of paper mache. Somehow it reacts 
with the ingredients of the glue, and makes it softer and brittle overtime. 
It's not just one formula, I've tried three different artist quality brands, 
and they reacted the same way. (sidenote: Another reaction to avoid is 
mixing Liquitex Gesso with Weldbond, it turn into a weird cheese-like turd)


Questions welcomed.














and fully cured (it will be stiff)



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