Plain felt is thick and durable, but it isn't stiff enough to retain a 3-D shape for a project such as a brimmed hat without first treating it. Treating individual pieces of felt with a homemade or store-bought fabric stiffener is suitable for a wide variety of projects. The stiffener that works best for your project depends on the intended use; for instance, a glue-and-water stiffener offers a permanent treatment, while pre-made solutions are handy for temporary stiffening projects.
Things You'll Need
Old plastic tablecloth
Craft sticks or plastic spoons
Binder clips or stickpins
Wooden spoon or empty can
Spay starch or fabric stiffener
Cover the work surface with an old plastic tablecloth to protect it from glue and water spills. Set a plastic tub atop the tablecloth.
Pour equal amounts of water and glue in the tub, stirring them with a craft stick or plastic spoon until completely blended. The liquid should be deep enough to completely cover the felt.
Place a single layer of felt in the liquid in the tub, pushing the material down with a craft stick to submerge it completely. Flip the felt over after a few minutes using your fingers or tongs.
Set a sheet of waxed paper near the tub. Remove the felt from the tub, letting excess liquid drip back into the tub. Blot excess liquid out of the felt between layers of paper towels. This prevents the felt from looking as if it has a thick layer of glue on it after it dries.
Smooth the felt piece out on the wax paper, ensuring it rests completely flat, as it will harden in position. Allow the felt to dry completely, which may take at least 3 hours.
Shape your felt project piece as desired. If it is a 3-D shape, such as a cone, use binder clips or stickpins to hold the desired shape as you work.
Set the felt atop a piece of wax paper outdoors or in a well-ventilated area. If the shape requires spraying the underside as well, rest the felt creation atop a wooden spoon or an empty can instead.
Shake the spray stiffener container, if it is an aerosol variety, or twist the nozzle to a spray setting if it is a spray bottle. Spray the felt using continual, slightly overlapping strokes, following package instructions, which may vary by brand. Once the entire project is covered, allow it to harden for several hours or as recommended on the stiffener container. Spray-on fabric stiffeners such as starch tend to be less firm and less permanent than the glue-and-water solution.
Felt may bleed when using wet methods to stiffen it. If stiffening multiple pieces of felt using the same solution, start with the lightest color first to avoid color transfer.
Always work in a well-ventilated area with spray-based fabric stiffeners in case they contain strong-smelling chemicals.