If you have seen a rosin jar labeled 90–120u or 45–159u, the “u” refers to micrometers. In hash making, micron-sized screens separate resin heads and plant material by particle size before the hash is pressed into rosin.
What the number describes
A micron range tells you which sieve sizes contributed to a hash fraction. For example, a 90–120u selection is narrower than a broad full-spectrum range.
Does a smaller or narrower range automatically mean better rosin?
No. Micron range is useful context, not a universal score. Cultivar, resin quality, maturity, wash technique, contamination level, drying, pressing and storage can all matter more than the number printed on the jar.
Why use different ranges?
Different cultivars produce resin heads with different characteristics. A maker may choose a narrow range for a particular expression, or combine a broader set of fractions to preserve more of the cultivar's overall character.
How to use micron information when shopping
Treat it the same way you would treat roast level in coffee or proof in spirits: one meaningful detail among several. Compare it with cultivar, flavor, terpene profile, texture and batch information.
PCC surfaces micron range directly on qualifying Pure Press product cards so you do not have to dig through a paragraph to find it.
