“With no ‘true’ photographs to play with, Karimi worked from the composer’s death mask, which was made by sculptor Jean-Baptiste Clésinger a few hours after Chopin’s death, on 17 October 1849.
“The artist also used a lock of the composer’s hair, which is kept in the Warsaw Museum.
“All the sculpting and colour mapping was done using ZBrush, a digital sculpting tool that combines 3D and 2.5D modelling, texturing, and painting. For Chopin’s floppy locks, Karimi used XGen, an interactive tool used for creating realistic-looking hair.” https://www.classicfm.com/composers/chopin/artist-creates-realistic-portraits-face/