High temperature clear coating on ceramic or glass?

[dwyejj]

I have an application with the following clear coat requirements on ceramic/glass:

Minimum 50 micron thick clear coat that can withstand 230 degC.
The clear coat is to serve as a medium for application of decorative decal over aluminium/ceramic/glass substrate by a sublimation process.

Any suggestions for materials that can be applied via a wet or powder paint process?

Sincerely,
John