This video gives an overiew of a shim that fixes the spacing issue in my Acrylic LED Signs, which use 2mm stock, while the base is designed for thicker material.
(https://savagecircuits.com/wp-content/uploads/2025/04/Acrylic_LED_Sign_Base_Shim_12a.jpg)
CLICK HERE TO GO TO THIS VIDEO ON THE SAVAGE///CIRCUITS WEBSITE (https://savagecircuits.com/acrylic-led-sign-shim-overview/)