AMMO by MIG Accessories - Masking for Modelling
Item: Masking Sheets (280x195mm)

From the Manufacturer:

All-purpose airbrush masking sheet for use with all paint and surface types. Each sheet size of 280x195mm allows for large and small designs to be traced and cut by hand or by plotter. This light transparency can also be placed on a drawing or surface for tracing or copying patterns and shapes. This masking material is designed to be used with every type of paint for clean definition and lip free edges while leaving no trace of adhesive. Always take precaution when masking painted surfaces to avoid damage to the base layer.

Flexibility allows masking to be used to secure joints while glue cures, and as an edge guide for engraving details on the plastic. This material cuts clean and easily with scissors or a sharp blade, and can even be cut on the model if necessary.