Sharpen a Knife by Cutting Cardboard ? The Real Answer

by | May 6, 2021 | cutlery and knife | 0 comments

Almost everyone knows the funny fact that you can sharpen a knife by cutting through cardboard.

While most knives are designed to hold their edges for a long time, they also get dull over time.

So when these edges become blunt, the ultimate thing to do is sharpen them.

You can invest in a sander or resort to DIY tricks such as. Cardboard to sharpen your blade.

So cardboard sharpens a knife?

The short answer to this question is yes. Cardboard acts as a leather strap when it comes to striking a blade to restore its edge. With cardboard, cut at an angle so that the surface of the board is sanded on the edge.

Damages cutting cardboard or knocking out a knife?

Does Cutting Cardboard Sharpen a Knife

Cardboard, like other paper products, requires you to be careful when cutting so as not to dull or damage the cutting edge.

Cardboard is made from recycled materials and is thick and heavy.

Therefore, cutting through this board may dull a thin blade, as the knife needs thicker material than it would be when thinner paper was cut out.

Overall, cardboard is not the best material to sharpen your blade as it can potentially damage the knife.

This is especially true if you regularly cut through cardboard when restoring the cutting edge.

What factors determine how a paper will affect a leaf?

While cutting through paper with a blade can sharpen the edge, it can also have a negative impact and blunt the knife.

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There are a few factors that affect how the paper affects the edge.

Some of these factors include:


The thickness of the paper determines how easily the blade will cut through the paper.

Thick paper contains larger filler particles and other materials that make it difficult for the blade to slide through.

On the other hand, thinner paper is less harmful to the edge.

This is because the paper is soft, making it perfect for sharpening blades.

Therefore, the thin paper will blur the knife more slowly than thick paper.


Thick paper is dense due to the high content of fillers and added materials.

As such, heavy paper will make your sheet dull.

Therefore, heavy paper may not be the best choice for sharpening your knife.

Ideally, the denser and thicker the paper, the more likely it can damage and dull your blade.

Top everyday items you can rely on to sharpen a knife

You do not need to have an electric sander or a sandpaper rod to restore the edge of your blade.

This is because there are a large number of objects in the kitchen that you can use to refine and straighten the cutting edge of your blade.

Some of these objects are like:

Coffee mug

It is common to find ceramic coffee mugs in most households.

These cups are perfect for straightening the edge of your blade.

All you have to do is turn the cup upside down and run the edge over the rough part of the base.

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Sand one side until it is finely finished, then turn to the other side.


Although sandpaper is not an object that you are likely to find in the kitchen, it is handy for sharpening your knife.

Use the coarse gravel to sharpen and finish the edge with the fine gravel for maximum sharpness.

Be careful when using sandpaper to sharpen your knives due to the risk of cutting your fingers.

Nail file

A nail file is a perfect alternative to sandpaper.

Both items are used in a similar way when it comes to sharpening your blade.

Run the edge of the blade against the nail file.

Maintain the best grinding angle for uniform and uniform sharpness.

A nail file is an excellent choice for polishing your blade before use if you do not have a honeycomb.

What makes a knife boring?

The primary reason why the knives become dull is due to repeated use.

Improper handling and use of the blade can also make it dumb.

For example, if you use a kitchen blade to cut through frozen and hard foods.

Washing the knife in a dishwasher can also potentially make the cutting edge dull.

Always take the best care of your knife so that it lasts longer and keep the edge long.


In a knife tip, cutting cardboard can sharpen your blade, but only if done carefully and with precision.

There are many other safer and more effective sanding options that you can use to restore the edge of your blade.

Always cut your knife after every few days to straighten the edge and extend its sharpness.

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