Coloring pages: patterns to color here or print

The three kinds of coloring page

• Quilt squares: a block of squares, each cut into four to nine shapes. Big shapes means 12 squares, medium 48, small 108. The pattern is the same turned over left to right or top to bottom.
• Round pattern: rings around a middle, like a flower seen from above. Big shapes means 12 points around and 4 rings, medium 16 points and 6 rings, small 24 points and 8 rings. Every side is a straight line, so the rings have corners.
• Window of colored glass: one tall box cut into panes of many sizes. Some panes are cut again on a slant, and some hold a diamond.
• Closed shapes: every pattern is made of closed shapes with straight sides, and no shape lies over another, so each one can be filled on its own.
• The pattern number: any whole number from 1 to 999999. The same kind, shapes and number make the same pattern on any device, so a whole table can color the same one. If we change how the page draws patterns, a number will make a different one.

On the screen and on paper

• Twelve colors: red, orange, yellow, light green, green, light blue, blue, purple, pink, brown, gray and black. The page writes the name of the color in your hand, and of the shape you fill, in words.
• Lines: thin lines print about 0.35 mm wide and thick lines about 0.8 mm. Thick lines are kinder to a young child’s crayon and to eyes that need a stronger line.
• How big it prints: one quilt page on a Letter sheet is about 19 cm wide and 25 cm tall. Four on a sheet are about 9 cm by 12 cm each, and small shapes get very small at that size.
• Printing your colors: choose “With the colors I put in here” and the first pattern on the sheet prints as you colored it. Color on paper uses ink, and a printer’s colors can look different from a screen’s.
• With a keyboard: the arrow keys step through the shapes one at a time, and after each step the page says the number of the shape and its color.

Every time the page is built, a program makes 1,800 patterns (200 of each kind and size of shape) and checks each one a second way, with code written apart from the page’s own. It checks that every corner is inside the box, that no shape is there twice, and that the areas of the shapes add up to the whole. It also drops 108,000 points on the patterns and checks that not one of them lands in two shapes. Then it measures the 18 ways the page can lay patterns out on a sheet.

What this page does not do

• It does not keep your colors. If you close or reload the page, or pick another pattern, they are gone. The pattern number brings back the pattern, not the colors. To keep a colored one, print it or save it as a PDF.
• It has no undo button. “No color” takes the color off one shape, and one button takes them all off.
• It does not draw animals, people, letters or scenes, and it cannot turn your own photo or drawing into a coloring page. Every pattern is shapes with straight sides.
• It does not mix colors or shade. A shape takes one of the twelve colors, edge to edge.
• It cannot describe the picture. With a screen reader you can step through the shapes and hear each one’s number and color, but the page does not say where a shape sits or what the whole looks like. Coloring on the screen mostly needs sight.
• It makes no promise about your mind or your health. It is something to color.
• It cannot see your printer. It has been tried in one browser’s print preview (Chromium, saved as PDF), where each sheet came out on one page; it has not been tried on paper from a real printer.