Using PVA glue to waterproof a dry papier-mâché ‘balloon head/mask’
before adding further pulp and laminations
The strength and rigidity of a papier-mâché ‘balloon head/mask’ will be affected by the
number of laminated layers of newspaper the children use. Older juniors working in
pairs can build up as many as 12-15 layers during the course of an afternoon, which
when dry form a very strong shell. Younger children may get bored with applying this
number of layers so you may have to settle with less. Hence, the papier-mâché shell will
have less strength. If two masks are required (one for each child), the balloon head can
be cut in half by the teacher, once it has dried, by using a Stanley knife. Further papiermâché pulp and layers can then be added. However, with a thin shell made from only a
few layers there is an additional issue, namely that applying further wet pulp and layers
will soften the shell because cellulose paste is water soluble even when dry. If it gets
too wet, it can lose its strength and begin to collapse. One way round this is to coat the
dry shell with watered-down PVA glue. When PVA dries it becomes waterproof and
hence will provide a barrier between any new wet papier-mâché and the dry shell
beneath.