Check the listing for details. Bickmore Kahl Hat Stiffener - Great for Fabric & Felt Hat Brims - Will Not Affec. Condition: New. Listed at 20.81 USD. Bickmore Kahl Hat Stiffener - Great for Fabric & Felt Hat Brims - Will Not Affect Tone, Texture, or Color. Directions: Always check for colorfastness in a hidden area before using. Shake well. Cover work area with a cloth.