Porträtstudie Unknown

Austrians Carl Angerer and Alender Gölsch invented a halftone method in 1879, patented in 1884. The system was a ruled glass single line screen turned 90 degrees after one half of the exposure in front of a sensitive plate to create a crossline negative. Angerer was forced to give up his patent in Germany because Meisenbach’s patent preceded his. In an 1883 sample book Probedructe von Chemigraphien und Heliotypien he referred to the halftones as “Heliotypie.” In the sample book the four halftones are each done with a different screen pattern indicating that the method was not fixed at that time. The crossed line screens on the four illustrations were 125 lines per inch to 133 lines per inch.

References

Hanson, David Checklist of photomechanical processes and printing 1825-1910, 2017 p. 8