Both. A 80 gsm ( = grams per square meter)A4 sheet has the same density as a 80 gsm A0 sheet (80 gsm= 80 gsm) but only 1/16th its weight (5g = 1/16×80g) since i

Both. A 80 gsm ( = grams per square meter)A4 sheet has the same density as a 80 gsm A0 sheet (80 gsm= 80 gsm) but only 1/16th its weight (5g = 1/16×80g) since it only has 1/16th its area.