A writing medium reservoir that exhibits clear drain of a writing medium,
and preferably in which the writing medium is readily visible to the user.
A method of making a writing medium reservoir that exhibits clear drain of
a writing medium, and preferably in which the writing medium is readily
visible to the user. The method may include forming the writing medium
reservoir by co-extruding an inner layer and an outer layer. In addition,
the present invention relates to a multi-layer tubular structure that
exhibits clear drain of a liquid, and preferably in which the relative
presence or relative absence of liquid is readily visible to the user.
