Indurate -

Historically, "indurated fibre" (like in Fibrotta products from the early 20th century) was a type of wood pulp product that was hardened and waterproofed, often used for items like fire pails or washbasins. To give you the best method, what are you trying to do? Are you doing origami and need crisp folds? Are you making paper mache/models that need to be durable?

Mixing school glue with water and applying it to paper with a paintbrush increases stiffness. For greater rigidity, multiple sheets can be layered together with glue and dried under heavy books to prevent warping. indurate

Are you trying to make paper look and feel like ? Are you making paper mache/models that need to be durable

For extreme hardening, particularly with papercraft or Pepakura models, coating with fiberglass resin is a common technique. Are you trying to make paper look and feel like

Here are the primary methods for indurating (hardening) paper:

Applying a thin, transparent layer of silicone gel to paper increases its strength. Sprays: Clear sprays, such as polyurethane or , can be used to stiffen paper models.