Stephen H. Horgan

• Horgan's half-tone and photomechanical processes
• Photo-engraving primer
• Photoengraving in black and color
• Engraving methods and photomechanical processes of reproduction
• Invention of rotary photogravure
• Photo-engraving
• Printing photogravure in colour
• Rotogravure in colours in the United States
• The father of half-tone
• The first book printed in North America
• The origin of the New York Daily Graphic
• To avoid screeny effect in half-tone work