Because it’s a GIMP plugin, you can script it using GIMP’s batch mode. Photographers creating a series of cyanotype-style prints will appreciate this automation capability.
It is actively maintained and works with the latest GIMP versions. cyan gimp plugin
# 4. The "Cyan" Shift (Channel Mixing) # A real cyanotype is blue in the shadows and bleached white in highlights. # We create a new layer filled with a deep Prussian Blue. bg_color = (15, 35, 75) # Deep blueprint blue bg_layer = pdb.gimp_layer_new(img, width, height, RGBA_IMAGE, "Blue Base", 100, NORMAL_MODE) pdb.gimp_image_insert_layer(img, bg_layer, None, 1) # Stack above original Because it’s a GIMP plugin, you can script
Unlike a simple "blue filter," Cyan simulates the chemical process’s unique contrast curve. Shadows turn deep, rich indigo, while highlights fade to pale, creamy white (not pure paper white unless you adjust it). Midtones gain that slightly granular, vintage texture. The plugin includes controls for: bg_color = (15, 35, 75) # Deep blueprint blue bg_layer = pdb