Each set is a complete prompt. Copy it, or open it in the studio with the model, aspect ratio and resolution it was written for.
Portrait Coloring Page
The standard approach: one person at a medium level of detail.
5 creditsNano Banana 2image → image2:3 · 2K
Reference photos: One portrait. The hairstyle silhouette and the shapes of the clothing are converted into line art, while the facial detail is simplified moderately.
Convert the reference portrait into a printable coloring book page. Keep the person recognisable through their hairstyle silhouette, hair volume, face outline and the shapes of their clothing, while simplifying the features into clean line art: eyes as simple outlined shapes with a small pupil circle, eyebrows and mouth as single strokes, nose as two short marks. Line rules: pure black lines on a pure white background, a thicker outer contour around the whole figure and thinner interior lines at about half that weight, every enclosed area closed with continuous lines so colour cannot leak, no tiny gaps at line junctions, no hatching, no stippling, no grey fills, no gradients, no textures, and every area left either white or outlined. Usability: make each enclosed area at least the width of a marker tip, which means merging small features into larger shapes and removing jewellery, fine patterns and hair strands. Composition: the figure fills about 75 percent of the page, centred, with a clear white margin around the whole drawing; add three or four simple decorative elements around the figure, such as a few leaf outlines and two clouds, all drawn in the same line weight as the interior lines. The background stays pure white with no paper texture. Vertical 2:3 page layout, print-ready, no shading, no text, no watermark.
Negative prompt
grey shading, hatching, gradients, paper texture, broken lines, tiny details, photograph, colour, text, watermark
Reference only — the image models available here do not take a separate negative prompt, so this list is guidance for editing the prompt above.
Why this works: The standard entry. If the detail is too fine, move the sentence about each enclosed area being at least one marker tip wide further forward and name the jewellery and the patterns to be removed.
Pet Coloring Page
The markings are expressed with lines, including the patches, the white socks and the tail.
5 creditsNano Banana 2image → image1:1 · 2K
Reference photos: One photo of the pet. The markings have to be drawn with lines, including the patches, the white socks and the tail rings, and that is what makes a pet coloring page recognisable.
Turn the pet in the reference image into a printable coloring page. Keep the animal recognisable through its head shape, ear shape, muzzle length and tail shape, and express the markings as line patterns: the stripes or patches are drawn as outlined shapes with the same positions as in the reference, the white paws are separated by a line at the same height, and the tail rings are drawn as bands. Line rules: pure black lines on a pure white background, a thicker outer contour and thinner interior lines at about half that weight, all shapes closed with continuous lines and no gaps at junctions, no shading, no grey, no hatching, no gradients, no texture. Usability: every enclosed area at least as wide as a marker tip, so simplify the fur into a few large shapes rather than many small ones, and drop whiskers to two lines per side. Composition: the pet sits centred and fills about 70 percent of the page, with a clear white margin on all sides, plus four simple decorative outlines around it such as a ball, a bone shape and two paw prints drawn in the same interior line weight. Square page, pure white background with no paper texture, print-ready, no text, no watermark.
Negative prompt
wrong markings, grey shading, hatching, gradients, furry texture, broken lines, tiny details, colour, text, watermark
Reference only — the image models available here do not take a separate negative prompt, so this list is guidance for editing the prompt above.
Why this works: The pet entry. The markings have to be turned into shapes drawn with lines; if the markings are lost, list the positions of the patches item by item.
Family Scene Coloring Page
You want a complete scene such as a house, a garden or a birthday party.
7 creditsNano Banana Proimage → image3:2 · 2K
Reference photos: One family photo or casual snapshot. The scene entry fills in the background to make a complete picture, so the original composition does not have to be perfect.
Turn the reference photo into a printable coloring page showing a full family scene. Keep each person recognisable by their hairstyle silhouette and clothing shapes, simplified into outline forms: three figures standing together in a garden with a low fence, a tree with four large leaf clusters, a small table with a cake and three plates, and two birds drawn as simple outlines in the sky. Simplify every figure down to head, body, arms and legs with clean contours, and express facial features with the fewest possible marks. Line rules: pure black lines on pure white, a thicker outer contour for each main shape and thinner interior lines at about half that weight, all areas closed with continuous lines so no colour can leak, no shading, no grey, no hatching, no gradients, no paper texture. Usability: keep every enclosed area at least as wide as a marker tip, so merge small details such as fence slats, cake decorations and leaves into larger shapes. Composition: a wide 3:2 page with the scene centred and a generous white margin all around, readable at A4 print size. No text, no watermark, print-ready line art.
Negative prompt
cluttered small details, grey shading, hatching, gradients, textures, broken lines, colour, text, watermark
Reference only — the image models available here do not take a separate negative prompt, so this list is guidance for editing the prompt above.
Why this works: The scene entry. When there are more than three people, reduce them to three first, because each extra person makes line closure and area size worse.
Text-Only Coloring Sample
Page samples and low-cost load testing.
3 creditsNano Banana 2 Litetext → image1:1 · 1K
A printable coloring book page showing a generic child standing beside a large tree, holding a balloon, with a small dog sitting at their feet and three simple clouds above. Line rules: pure black lines on pure white, a thicker outer contour and thinner interior lines at about half that weight, every shape closed with continuous lines and no gaps, no shading, no grey, no hatching, no gradients, no texture and no paper grain. Usability: every enclosed area at least as wide as a marker tip, so facial features are reduced to simple outlined shapes and textures are merged into large areas. Composition: the scene is centred and fills about 75 percent of the square page with a clear white margin on all four sides, readable at A4 print size. Clean line art suitable for children, print-ready, no text, no watermark, no colour anywhere.
Why this works: The text-only sample entry, the cheapest one. It covers pages that have no photos, and it also makes it easy to swap the scene under the same rules.