The scroll, designated 1QIsa-a, was among the first group of manuscripts taken from Cave 1 near Qumran in 1947 and sold through an antiquities dealer in Bethlehem; it was eventually acquired for Israel along with three others of the original seven. It is written on parchment in seventeen sheets stitched together, about 7.3 metres extended, and carries the entire book of Isaiah in fifty-four columns, with only small lacunae. No other biblical scroll from the caves approaches it for completeness.
The hand is a Hasmonean formal script. Dating rests on two independent methods that agree: palaeography places it at roughly 125 to 100 BCE, and radiocarbon testing has returned ranges consistent with that, a 1995 Arizona measurement giving 202 to 107 BCE. Palaeography remains the tighter of the two.
The manuscript is not a pristine object. It is the work of more than one scribe, with a change of hand around the midpoint. Corrections were made both by the original copyists and by later readers: letters cancelled with dots, words inserted above the line, whole passages added in the margins, and a substantial omission in chapter 40 supplied vertically down the side of a column. Paragraph divisions, sense breaks and occasional marginal marks whose meaning is not agreed are visible throughout.
It is, in other words, a used copy rather than a display scroll, and its wear at the beginning and along the edges suggests it was handled. That makes it evidence not only for the text of Isaiah but for how a text was copied, corrected and read in Judaea in the last century BCE.