I wrote this instructable for students trying to do isometric drawings in lockdown.

In a normal world, I'd tell you to buy a pad of isometric grid paper, or print some out from online sources, but that is not always possible - lockdowns and a general lack of home printers get in the way,

So, I came up with this. With compass, pencil, ruler and scissors you can create a template that will let you create isometric grids of your own.

Safety warning: this project uses sharp knives.

Step 1: Needful Things

You will need:

Thin card, such as a cereal packet or frozen-food box.
Pencil
Compass
Ruler
Scissors (if your scissors have rounded ends, you will need a sharp-pointed knife as well, such as a craft knife, pen knife or fruit knife)
Cutting mat, chopping board, or other surface safe to cut on.

Useful extras:

Rubber/eraser
Fineliners
Sharp craft knife

Step 2: Draw a Cube

You can use a pencil-and-compass to draw a cube, using the ancient trick for drawing a hexagon.

I set my compass to a radius of 50mm / 5cm, but this works in whatever units you prefer.

Draw the circle, then, keeping the compass at 50mm, I marked six equal steps around the circumference of the circle, and drew a hexagon.

I then connected every other point of the hexagon to the centre, drawing an isometric cube.

Step 3: Divide the Cube

I then marked 10mm divisions along every edge of the cube, and joined them across each face of the cube, dividing each face into 25 isometric squares.

At this point, I inked my lines.

Partly, this adds life to the template, but mainly because it is easier to photograph than the pencil...

Step 4: Drill the Cube

At all the points where lines meet or cross the edges of the cube, you need a small hole.

Use any sharp-pointed knife to drill a tiny hole through the card. The holes need to be just large enough for the point of a pencil.

Step 5: Hollow Out, and Trim.

Just in case you need to use the template over larger areas, I'd recommend cutting the middle out of each face.

That will let you line up the template with lines you have already drawn.

You also need to cut your template out of the card - I drew points 10mm out from the corners, and cut out another hexagon.

Step 6: Using Your Template

Remember that this template is just a guide - it is not, and cannot be, as precise as a purchased template, or one manufactured with precision from a more durable materials.

Holding the template firmly in place, poke your pencil through each holes to make a dot on the paper.

If you can, do this with a soft pencil, so that it will make a visible mark without much of a dent in the paper.

Once you've done all the holes, draw light, faint lines across the dots - they will build up into a grid of triangles.

Use the triangles to guide the lines of your sketch - you can draw on the lines and be blocky, as my example here, or draw between the lines to make your details finer.

As you get happy with where your lines are going, you can firm them up, even ink them, and shade the faces of your object to emphasise the 3D aspect of the image. If you ink your lines, you can rub out the traces of using the template as well.

Enjoy your new tool, and, if you feel the urge, share what you draw in the comments.