A v-cut, also known as a v-groove, is a type of cut made into a material to allow it to more easily fold or bend. V-cuts consist of two angled cuts that form a “v” shape when looked at from the side. They are commonly used when a material needs to be folded, such as when creating boxes, pop-up cards, origami models, and more.

The depth and width of a v-cut can vary depending on the material being cut and the required functionality. Controlling these two factors is important in achieving a properly functioning fold in the material. In this article, we will explore what v-cuts/grooves are, the optimal depth and width to use, and how to cut v-grooves into different materials.

What Are V-Cuts and V-Grooves?

A v-cut/groove is a wedge-shaped cut made into a material, such as paper, cardboard, wood, plastic, or metal. The wedge cut allows the material to more easily bend at the point of the v shape. The v-cuts are placed strategically to form hinges that allow a flat material to fold into a three-dimensional object, like a box.

The v-cut gets its name from the v-like appearance when looking at the cut from the side. The two angled cuts that form the v shape meet at a point called the vertex. This vertex is the deepest part of the cut. The depth refers to how far the cut goes into the material, while the width refers to how wide the opening of the “v” shape is.

Diagram of a v-cut showing the depth and width

V-cuts allow materials to fold along the line of the vertex easily and cleanly. Without v-cuts, trying to fold a material would result in uneven tearing and wrinkling. The v-cut concentrates the fold into a controlled line.

The Optimal Depth of V-Cuts/Grooves

When creating v-cuts, the depth is an important factor to consider. The depth will depend on the thickness and density of the material being cut. Some general guidelines exist for optimal v-cut depth:

• For paper and cardstock, the depth should be around 75% of the material thickness
• For thin plastics, acrylic, or metal, the depth should be 50% of the thickness
• For thicker plastics, wood, and metals, a depth of 33% of the thickness is ideal

Going deeper than the guidelines above risks weakening the material too much at the fold lines. Not going deep enough results in stiff folding that can cause cracking.

There are a few ways to determine the target depth:

• Use calipers to measure exact material thickness and calculate percentages
• For paper, an optimal depth is generally around 0.02 inches to 0.05 inches
• Refer to v-cutter tool instructions for depth guidances

Precision is important for consistent folds, so taking material thickness into account ensures proper v-cut depth.

The Ideal Width of V-Cuts/Grooves

The width of a v-cut refers to the open space at the top of the v shape. The width determines how much space there is for the folded material to bend.

Some general guidelines exist for optimal v-cut width:

• For paper and cardstock, a width about 10% of the material thickness is ideal
• For plastics, acrylic, wood and metals, a width of 5% of the thickness is recommended
• Width may need to be slightly wider on thicker, denser materials

Having a width too narrow can result in material tearing or buckling at the fold. Having a width too large reduces structural strength around the folded areas. The right width provides clean folding without weakening the material.

As with depth, taking precise thickness measurements allows calculation of an ideal width. Err on the wider side if unsure. Depending on the use case, v-cut width can range from 0.003 inches for thin paper/cardstock to 0.25 inches for thicker plastics and woods.

Cutting V-Grooves and Hinges

Now that the optimal v-cut depth and width have been established, it’s time to actually cut them. V-cuts can be made using various tools depending on the material:

Paper and Cardstock

• V-scoring tools – These function like letter openers and use a v-shaped blade to score the paper. Good for origami.
• V-slitters – Manual tools that cut a v-notch into paper. Often used for scrapbooking.
• Die-cutting machines – Automated machines that use steel rule dies with v-shaped blades to cut shapes and hinges.
• Laser cutters – High power lasers can cut v-grooves into cardstock with precision.

Plastics and Acrylics

• Table/band saws – The blade angle can be adjusted to cut v-grooves into plastic sheets.
• Laser cutters – One of the most precise methods for getting clean v-cuts in plastics.
• CNC routers – Computer numerical control routers can be programmed to cut patterns of v-grooves.

Metals

• CNC mills – Computer controlled mills with v-shaped carbide cutting bits. Can achieve tight tolerances.
• Waterjets – High pressure water mixed with abrasives cuts through metal leaving smooth v-cuts.
• Plasma cutters – An angled plasma torch tip can be used to cut metal and achieve a v-shaped kerf.

Wood

• Table saws – Angled to the blade to create v-grooves across wood stock.
• CNC routers – Programmable routers are versatile for cutting custom v-cut patterns.
• Laser cutters – Can v-cut and etch designs into wood products with high accuracy.

The key is using a sharp blade, precise angle, and smooth motion when executing v-cuts to get clean edges and proper depths. Going slow improves control and reduces tearing. V-cuts can be made across full sheets or custom located based on fold lines.

Applications of V-Cuts and Hinges

Now that the fundamentals of cutting optimal v-grooves have been covered, let’s look at some of the useful applications. V-cuts create living hinges at fold lines that allow materials to transform from 2D to 3D. This functionality enables many creative uses.

Packaging and Boxes

Boxes assembled from laser cut or CNC routed v-cut cardstock have clean, precise folds and seams. The v-cuts concentrate the folds along the intended lines, preventing warping and buckling of the material. They can produce packaging prototypes and custom shipping boxes.

Pop-Up Cards and Paper Crafts

V-grooves make multi-fold origami and pop-up cards possible. The v-cuts act like hinges that allow sections of paper to pop into 3D shapes when opened. They facilitate intricate paper crafts and sculptures.

Kinetic Art and Toys

V-cuts in materials like wood, plastic, and metal enable movement and articulation for kinetic sculptures and automata toys. The v-cut hinges act like joints or pivots for parts that can rotate or shift to create motion.

Model Building

Architects and model makers utilize v-cuts to add living hinges to models for flaps, doors, and folding elements. This allows models to take on intricate and animated qualities.

Product Prototypes

V-cuts help turn 3D CAD designs into physical prototypes. Consumer product designers can simulate folding and articulating features with properly placed v-grooves. This accelerated evaluation of concepts.

Overall, any application where precise and controlled folding of materials is required can benefit from strategically located and properly cut v-grooves. Their ability to function as living hinges makes them an indispensible tool.

Frequently Asked Questions About V-Cuts

Here are answers to some common questions related to v-cuts and grooves:

How are v-cuts different from perforations?

Perforations consist of dotted cuts that are spaced apart to allow tearing. V-cuts are one continuous cut in a v-shape that functions as a hinge line. Perforations tear, while v-cuts fold.

Can v-cuts be made in thick materials like wood?

Yes, v-cuts can be made in thicker and denser materials like wood using table saws, CNC routers, or laser cutters. The depth and width may need to be adjusted to account for the thickness.

Do v-cuts need to go all the way across a material?

No, v-cuts can be strategically placed only where folding hinges are needed. They don’t necessarily need to span the full width of a material. Discrete v notches can be cut.

Should the angle of the v shape be 90 degrees?

The v shape angle determines how far open the material can fold. A narrow 60 degree v is good for compact folding. A wide 120+ degree v allows a greater range of motion. 90 degrees is a common medium angle.

How precise do v-cut measurements need to be?

Consistent depth and width are important across v-cuts, but precision down to 0.001 inches isn’t necessary for most materials and applications. Tight precision matters most when folding needs to be highly controlled.

Conclusion

V-cuts and v-grooves are an important tool for introducing living hinges and controlled folds into materials like paper, plastic, wood and metal. By following the proper guidelines for depth and width relative to material thickness, optimal v-notches can be achieved. The right tools, blades and settings are needed to get clean, smooth v-cuts. When done correctly, v-cuts enable materials to transform from flat sheets into functional folded and articulating structures. The applications range from packaging to complex pop-up paper crafts. V-cuts are fundamental when precision folding is required.