Tuesday, June 11, 2013

My Current Paper Mache Strip Method

This article will be updated to always reflect my preferred  method.

A simpler article, with pictures, is available on this very blog:

Let's not forget the classics!
Paper Mache strips, if applied properly, can be extremely detailed, extremely rugged and durable, and surprisingly lightweight.  I dare say that my paper mache is stronger than wood, and can rival a lot of plastics when it comes to resisting impact. 

Plus, it takes primers and paints into itself, preventing the common chipping or flaking problems that occur with the usual cast plastics.

My current method for detailed paper mache hollow heads, cast directly onto plastalina or ceramic clay:

Once my clay model is approved, I take good reference pictures of it in the major angles.
Then I carve it out some more to make the whole thing skinnier, to compensate for the thickness of the paper mache.  I also increase the depth and width of every crease. I also remove eyelids, as they would just get bulky with the paper over it. 

I pre-tear tiny strips of thin Kraft paper, and tiny strips of coffee filters. Each strip is the size of my pinky finger, and I tear them smaller as needed, for the more detailed areas. It feels like a waste of time at first, but overall, you save time, because you won't have to fight with the paper to prevent wrinkles.
Doing this in advance saves a lot of time, as it's easier to do with clean, dry hands.

My glue is either tapioca paste, or corn starch paste, depending on what I have on hand. I think Tapioca is stronger, but I cannot confirm this scientifically. I do prefer the tapioca paste for the consistency and the ease of preparing it.

I cover the clay head with strips of brown paper towels, using only water as a "glue", keeping it moist with a spray bottle until the whole head is well covered. Then I gently brush a coat of my paste over the whole thing, to hold it down and prevent lifting. This is the separation layer, but later, it will be integrated into the actual paper mache.  

I apply the paper strips with my hands mostly, dipping my fingers in the bowl of paste (never dip the paper).
I do use a stiff brush to get into the detailed areas. More overlap means more strength, and crisscrossing, to vary grain direction of the paper, adds even more strength.
Once I have three or four layers, I can use a metal modeling tool to define the paper in the crease, and I can burnish the whole thing to remove wrinkles and air pockets. I don't overdo it, because I know this type of paper mache, thanks to the type of glue used, is very easy to sand smooth once dry.

To see clearly where I need to add paper, and not confuse with the previous layer, I finish each layer by adding a counting layer. Some artists just change to a different color or texture of paper, but I prefer to keep using the same paper, to have consistency of strength. So my counting layer is just the same paste, mixed separately with a small amount of dry pigment. This means the counting layer becomes part of the paper mache, and does not create a barrier like a coat of paint would.

I apply about 4 layers of Kraft paper in one work session, then I make it dry in front of a fan at lowest setting (to save energy), overnight (8 hours).  I use a pencil to draw the cut line where I want it, Add some alignment lines to help with the reassembly later, then I use a pen knife to cut it.
Usually, I cut behind the ears, to separate the front from the back.
Make sure you have plenty of time to cut AND re-assemble the two parts in the same work session, because if you cut and leave the two halves separate for a few hours, they will warp and become more difficult to assemble again.

Once I have some dry paper mache to add onto, I must make my glue a bit more tacky, to prevent the new paper from sliding and shrinking, creating major wrinkles. The current solution is to add just a tiny bit of pva glue to the paste. I'd like to understand the chemical reasons for the crawling effect, so I could avoid using the pva altogether.
 To assemble, I align the lines, use masking tape to hold the head together, but most of the seam is still exposed.
Where there is no tape, I add longer strips of the same Kraft paper as before, crisscrossing and overlapping a lot.
When the strips have had time to grab onto the dry paper mache, I remove the tape and add strips there as well.
When the whole seam job has dried, the whole head can be sanded, and any modification, such as the sealing of the neck opening, or the addition of some wooden parts, is done with coffee filters and the sane tackier paste. 
When all the shaping is complete and dry, it can be sanded smooth and then covered with finer papers, to add a smoothness that is not too "dead". I start with coffee filters, and finish with brown paper towels.

When I'm sure everything has the texture I want, I dry the head one last time in my drying oven which I only use for this final stage. It,s a large cardboard box, with a hole on the side for the nozzle of my hairdryer. The item goes in there, a weight is put over the flaps of the box to keep them shut, and I activae the hairdryer at medium heat for   
 about 30 minutes, then I place the piece back in front of the fan for the possible remaining moisture to evaporate with the heat.

When this feels bone dry everywhere, I apply a coat of orange shellac, and let dry. I add another coat, and let dry.
Additional sanding can be done at this point, but shellac will have to be added again.

I cannot apply the primer directly on the paper mache, because it penetrates too much, and makes it soft.
this is why I use shellac first, and it also provides an additional layer of protection.

Then I add a primer, which will protect the shellac from alcohol, which is what I use for cleaning the insides of my  puppets.  The primer I use nowadays is Zinsser bull's eye 1-2-3 (waterbased version). It is a Primer-sealer, stain killer, meaning it's designed to capture and mask odors and stains in the walls, if replacing the offensive area is out of the question.   I find this sealer too thick, next time I use it, I'll try diluting it a bit.
I apply three coats of it, at least, with a soft, flat brush. I want this to be opaque.
The primer has made the paper mache a slight bit more flexible, and it is also weak against scratches for the first few hours.  Just like with acrylic paints, I only judge the final strength 24 hours after it feels dry to the touch.
But it can be painted immediately after it feels truly dry to the touch.  If you paint too early, the acrylic will crack, as it has a different shrinking rate than the primer.

This has worked well for quite a few Theater masks and puppet heads I have made in the past three years.

This primer allows me to paint with acrylics, or oils.