The famous, almost completely preserved Isaiah Scroll was discovered in 1947 in a cave near Qumran at the northern end of the Dead Sea. It is clear visible, that this leather scroll consists of leather panels that were sown together. The scroll is unrolled here to Isaiah 40; there the scribe forgot to copy one passage; the mistake was corrected by writing this passage vertically into the margin. Four dots are also visible between two lines; here its corrector is said to have subsequently added in Old-Hebrew script the name YHWH that was forbidden to pronounce in Hebrew. Isaiah 40
Picture Source: 1000 Bible Images. Stuttgart, Germany: German Bible Society, 2009.