After reviewing the potential undercuts on the plasticine model of the squirrel mask, I decided that the ears were going to to cause more hassle than I wanted for this particular mask. Instead of creating a negative plaster mold, I have opted for using the plasticine as a positive mold. I am using a layering paper mache technique with newsprint, unbleached coffee filters, and wood glue (TiteBond II).
The first time I read of using newsprint and coffee filters was about a year ago on the puptcrit mailing list from an avid contributor whose blog you can find here: Creaturiste’s Laboratory. Mathieu (a.k.a. Creaturiste) is an advocate of paper mache for puppet and mask construction. And rightfully so! With proper techniques, supplies, time and patience, it is possible to create durable works of art that have lasting potential equal to or greater than other materials.
Starting with a layer of wet newsprint torn into small pieces, I am able to create a protective cover for the clay or plaster mold.
There is no glue involved in the first layer except for at the end. I soak the newsprint strips in water and then apply them to the clay mold. For detailed sections, I tear the strips even smaller.
Once the entire mold is covered, I carefully apply a light coat of glue diluted with water to connect and seal this newsprint layer. The reason I use newsprint instead of coffee filters for this layer is that if I were to use coffee filters, the glue may very well soak through to the mold and adhere to the surface. The newsprint forms a thick enough barrier for this not to happen but is still thin enough to produce good detail.
Allowing the newsprint and glue to fully dry before apply coffee filters allows the layer proper time so as not to warp or deform. I have not tried skipping this step as I usually have plenty other tasks to attend to that I have no need to jump directly to applying the next layer.
Up next will be the application of unbleached coffee filters and glue which is a very time consuming process with a larger mask such as this one.