Prussian Blue Portrait Generator: Turn a Photo into a Bold One-Color Ink Sketch

It is a one-color illustration: everything is drawn in a single deep blue on a light ground, with no other hues. The AI uses fast, rough brushstrokes, sharp angular accents and lines radiating out from the subject, so it reads more like a hand-cut linocut or woodcut print than a soft watercolor. Faces stay recognizable, but small details are simplified into bold shapes.

Prussian blue is the default and the classic choice. The deep blue looks like ink or a cyanotype and suits portraits and pets. Crimson red is louder and works well for sports, music and poster images. Emerald green feels calmer and stands out in a feed full of blue and red. The style is identical in all three; only the ink changes, so running one photo in two colors is an easy comparison.

Photos with clear light and shadow work best, because the style turns tones into hard contrast. A side-lit face, an athlete mid-movement or a dog running all give the brushstrokes something to follow. Flat, evenly lit selfies still work but look calmer. Keep the subject large in the frame, skip heavy beauty filters, and upload a sharp JPG or PNG.

Each run makes one image. It costs 8 credits with GPT Image 2.5, the default model, and 4 credits with Nano Banana 2.1. New accounts get free credits and you can collect more through the daily check-in, so you can try a few colors before deciding whether you need a paid plan.

GPT Image 2.5 usually gives a more deliberate composition and cleaner energy lines, and it always returns a square image, which is handy for avatars and prints. Nano Banana 2.1 costs half as much and is good for quick tests of a color or a photo. If the first result feels too busy, try the other model with the same photo before changing anything else.

You can download the image and print it as a poster, card or zine page. Because it uses a single color, it also translates well to screen printing or a one-color stamp. For anything you plan to sell, use a photo you own or have permission to use. For large prints, start from a sharp, well-lit photo so the lines come out clean.