Clean the inside of the wooden box thoroughly
Lightly sand the interior surface
Remove all dust and debris
Apply a thin layer of strong adhesive suitable for wood and polymer clay
Condition the polymer clay until soft and workable
Roll the clay into thin sheets
Cut the sheets to fit the inside panels of the box
Press the clay firmly onto the wood surface
Smooth seams and edges with your fingers or a clay tool
Trim excess clay from corners and edges
Bake the clay according to the manufacturer’s instructions
Let the box cool completely
Check for loose edges and reattach if needed
Seal the clay if desired with a compatible finish
Avoid exposing the box to excessive heat after lining it with polymer clay