I dont know what the difference between 200/300 micron is.
It's 50% increase or 33% decrease! 1/5 or 1/3 of a millimetre are the approx dimensions.
I use a 200 micron for filtering honey for jarring. You may want to filter twice as 300 micron will filter much faster than the finer one and remove most of what would blind off the smaller appertures.
I normally screen through a seive (from the extractor into buckets), which removes most of the wax and bits. Then just through a filter cloth (when 'melted' for bottling), allowed to stand in the honey tank (air up and any unlikely bits down) for a couple of days or so, then bottled.
'Show' honey would be treated differently.
Regards, RAB