8 mm dot grid paper
Eight millimeter dot spacing, coarse enough that the grid guides without constraining.
Opens with these settings already loaded. Change anything you like, then download as PDF, PNG or SVG.
Coarse grids are an accessibility choice
A fine grid assumes steady hands and good near vision. Widen the spacing and lighten the dots and the same page becomes usable for someone with a tremor, with low vision, or simply with large handwriting. This is a real use case and an underserved one, because most printable dot grid defaults to a bullet journal standard that suits neither children nor older writers.
Sketching wants space, not structure
For thumbnail sketching and rough layout the grid is there to keep things roughly aligned, not to constrain where the pen goes. At 8 mm there are enough dots to judge proportion and few enough that they disappear behind a drawing. Tighter than about 6 mm and the dots start competing with the sketch.
Try 7 mm if this is slightly too open
Spacing preference is narrow and personal, and the gap between 7 and 8 mm is noticeable in use even though it sounds trivial written down. The 7 mm sheet is the intermediate step, and the generator will take any value if neither is quite right.
Printing it accurately
This only measures correctly if your printer doesn't rescale the page. In the print dialog set Scale: 100%, not "Fit to page" or "Shrink oversized pages". If you're not sure it worked, print the calibration page, measure the ruler on it with a real ruler, and it will tell you exactly what your printer is doing to the page.