Derived from Naskh and Taliq it is used extensively for copying Persian anthologies, epics, miniatures and other literacy works.
The Nasta'liq is a refined version of the Ta'liq script, although with elements of Naskh. Merging the characteristics of both scripts, such as the short vertical lines of Naskh and the long curved horizontal strokes of Ta'liq, it is skill used in Persia, India and Pakistan for writing in Persian, Urdu and Punjabi.
In terms of legibility, it's an improvement on the Ta'liq but harder to read than Naskh. The letters are a little hooked, similar to those of the Ta'liq script, and vary in thickness.
Although the arrangement of letters flows smoothly and in harmony, it is hard to write and is less readable than many other scripts.