Generator · Print-true
Printable isometric paper, true to 30 degrees
Isometric paper is vertical lines crossed by two sets of lines at exactly 30° from horizontal, so every cell is an equilateral triangle and all three axes share one scale. Set the spacing and paper size, then print it or save it as a PDF from the same dialog. The lattice is drawn as vector geometry in your browser and sized in true millimeters, with no watermarks or sign-ups, and nothing is uploaded.
How this generator works
The sheet is an SVG drawn in physical units, so every coordinate is a real millimeter. Vertical lines are placed at the spacing you set and centered in the printable area. The two diagonal sets are computed from tan(30°), so they cross the verticals exactly on lattice points and the page divides into true equilateral triangles; an eyeballed slope would give slightly skewed rhombuses. Because the diagonals are anchored to the vertical lines, the lattice repeats vertically every spacing × 2 × tan(30°), roughly 1.155 times the horizontal spacing. The readout shows the number of verticals and that row pitch before you print: 39 verticals and 5.77 mm rows at the 5 mm default on US Letter portrait, and 51 verticals in landscape.
Each diagonal is drawn straight across the sheet and then clipped to the content rectangle with an SVG clip path, so the pattern stops flush at the margin and stays out of your printer's mechanical dead zone. When you print, set the dialog's scale to 100% or "Actual size"; "Fit to page" rescales the whole sheet, and a 5 mm lattice then arrives as a 4.7 mm lattice. This page sets the print size to match your chosen sheet exactly and keeps the pattern inside a 12.7 mm default margin, so nothing needs rescaling, and at 100% the millimeters on paper match the millimeters on the readout. The methodology page shows how to check it with a ruler.
Only lengths along the three axis directions are to scale. A diagonal across a face does not come out at its true length, and a circle on a face is drawn as an ellipse. Line weights under about 0.2 mm print unevenly on consumer printers, which is why the default is 0.3 mm. A triangular grid has three sets of lines where a square grid has two, so it is also the pattern most worth keeping light.
Frequently asked questions
What is isometric paper used for, and is it the same as isometric graph paper?
Three main uses: 3D sketching and product design, where a box drawn on the lattice stays measurable; technical drawing, which needs the same scale on all three axes; and tabletop map-making, where the same triangular grid reads as hex terrain or as a room seen in three-quarter view. Anything you draw along one of the three axis directions can be measured straight off the sheet with a ruler. And yes, isometric graph paper is the same sheet under another name: both terms describe this triangular lattice.
Are the diagonal lines really at 30°?
Yes. Both diagonal sets are computed from tan(30°), so each sits exactly 30° from horizontal: 60° from each other and 60° from the vertical lines, which makes every cell an equilateral triangle. That is also why the vertical repeat is larger than the spacing you typed. On each vertical line, lattice points sit 2 × tan(30°) times the spacing apart, about 1.155 times the horizontal spacing (5.77 mm at the 5 mm default), and the readout reports that figure separately.
Is an isometric drawing the same as a perspective drawing?
No. In isometric projection parallel edges stay parallel: nothing converges on a vanishing point, and a cube's far edge is drawn exactly as long as its near edge. That keeps the drawing measurable, and it also makes it look slightly unreal. Depth looks flat, and a shape can seem to flip inside out while you stare at it. For a scene that looks photographic, use one-, two-, or three-point perspective on a blank sheet.
What grid spacing should I use?
Start with 5 mm for general 3D sketching: fine enough for detail without crowding the page. Product and engineering sketches with small features usually want 2.5 to 4 mm. Tabletop maps read better larger, at 10 mm; to match quarter-inch stock, switch the unit selector to inches and enter 0.25. Wider spacing also means far fewer lines and noticeably less toner: on US Letter, 10 mm prints 84 lines where 5 mm prints 167.
Will it print at true size, and does anything leave my device?
Yes, it prints at true size as long as the print dialog's scale is 100% (sometimes labeled "Actual size"); "Fit to page" shrinks the sheet. Set that once, then confirm with a ruler on the first printout. For a PDF, press Print and choose "Save as PDF" as the destination, and your browser makes the file itself. Nothing is uploaded, stored, or watermarked, because the sheet exists only inside this page and in your own print queue.
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