It’s 28 grams to the ounce* 0.91 yards to the meter (roughly 0.82 square yards to the square meter) so the 30 gms/square meter = 1 oz/square yard conversion is plenty close enough. Call it in the 110-125 gms/square meter range, which would correspond to the 3.7 to 4 and change ounces per square yard that passes for 4 oz. cloth here.
Hope that’s of use
doc…
and if you wanted to see something funny, back in the day it was a bunch of stoners with a metric-calibrated scale trying to figure out ounces while weighing controlled substances. Multiplying ( correctly) by 28 just wasn’t gonna happen.