Reuleaux triangle in cardboard – cutout 3–50 cm

You're sitting at the craft table with the children and the paints are ready. All that's missing is a basic shape not everyone has. The Reuleaux triangle in sturdy bookbinding board is made for afternoons like this. It's a triangle with three gently rounded sides. You can paint it, decorate it or write on it however you like. A simple cardboard shape becomes wall decoration, learning material or a small sign.

What changes for you

• You can start crafting straight away without cutting anything yourself. The triangle arrives ready laser-cut with smooth edges.
• Your projects get exactly the right size, from a small tag to a large wall piece. You can choose from 3 to 50 cm in 1 cm steps.
• You design the surface just the way you want, with paint, varnish, paper or fabric. The cardboard is untreated and left natural.
• Your decoration keeps its shape and doesn't sag. The solid board is 1.2 mm thick and 755 g/m², so it feels noticeably sturdy.
• You can craft with a clear conscience. The board is made from 100% recycled material.

Why this Reuleaux triangle makes a difference in everyday use

An unusual basic shape makes simple crafting something special. The three rounded sides look softer than a classic triangle and get noticed – on the wall, on a gift or in a shop window. Because the rounded sides already form an unusual shape, you need less effort for a good result. Crafting with children, money gifts or Christmas decorations: you have a reliable base. Your idea looks good on it straight away.

Material & finish

The bookbinding board is firm and keeps its shape. You can glue, paint or varnish it neatly, and it won't warp like thin card. The cutout is laser-cut in our own production in Pößneck, Thuringia. This creates the typical brown edge, which gives the shape a natural, handmade look. The surface stays untreated, so it is neither varnished nor glazed. That's ideal if you want to decorate it yourself, because paint and glue stick well to natural board.

Dimensions & technical details

• Material: bookbinding board, made from 100 % recycled material
• Material thickness: 1.2 mm
• Grammage: 755 g/m²
• Shape: Reuleaux triangle (triangle with three rounded sides)
• Size: choose from 3 cm to 50 cm, in 1 cm steps
• Cutting method: laser-cut, smooth edges with the typical brown laser rim
• Surface: untreated, not varnished or glazed
• Made in Thuringia, Germany

How to use the Reuleaux triangle

• Crafting with children: each child paints their own triangle. In the end, a colourful garland of one-of-a-kind pieces hangs in the children's room.
• For money gifts: stick notes and a short message onto the shape. Instead of an envelope, you hand over a gift that will be remembered.
• As Christmas decoration: combine several sizes and decorate them with paint and glitter. Your window gets decorations you can't buy anywhere.
• As learning material: the Reuleaux triangle lets you show children a geometric shape they can touch. Maths becomes tangible instead of abstract.
• In a shop or café: write on it and use it as a price tag or sign. The unusual shape keeps your counter tidy and individual at the same time.

Good to know about the shape of constant width

A Reuleaux triangle, also known as a curve of constant width, has an astonishing property. It is the same width in every direction, just like a circle, even though it is clearly a triangle. That's exactly why the shape works so well as learning material and a demonstration object. It also gets people talking about your decoration.

Care & durability

There isn't much you need to do. Store the cardboard dry and flat, and it will keep its shape. Avoid constant moisture, as the surface is untreated. If you want to use the triangle outdoors or in damp rooms, simply seal it with varnish or paint.

Options & what's included

• Available in sizes from 3 cm to 50 cm, selectable in 1 cm steps
• You receive the untreated Reuleaux triangle in bookbinding board in the size you choose
• Decorative items shown in the product photos are not included

Frequently asked questions

Can I paint and glue the cardboard? Yes, the surface is untreated and natural. Paints, varnishes and glues stick well.

Why are the edges brown? The triangle is laser-cut. This creates the typical brown edge with smooth, clean edges.

Which sizes are available? You can choose any size from 3 cm to 50 cm in 1 cm steps.

Is the material sustainable? Yes. The bookbinding board is made from 100% recycled material and is produced in Thuringia.

What counts is the moment a simple shape turns into something of your own in your hands. Then you proudly hang it up or give it away. Just choose your size and get started.