What is needed for a buff to work?

[Eilenberg]

What is needed for a buff to work?

Does the building need to be buffed at the start at the production (of, say, a damascene sword), at the end of the production or sometime during the production? The last thing could happen with a fish platter on damascene weaponsmith.

The answer to the above question could help me find out WHEN to buff.

Regards,
Jizz

[IMarduk]

yes what counts it the moment a production cycle ends (when the good is produced)