This $8 Knife Is the Only Purchase You Need to Make Before Prime Day Ends Tonight

Posted on July 11, 2025 by resourcefulman

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Like many Americans, I lament the way online shopping hurts local businesses that can’t compete with convenient , inefficient perks like Prime’s “free” two-day shipping . Like many Americans, I still buy a ton of stuff online because it’s so much easier to avoid lugging home a giant wad of toilet paper from Aldi (at least as a New Yorker, I can still be skeptical about walking to the grocery store). But that also means I have a whole bunch of cardboard boxes to deal with on Prime day or during the holiday season.

Every year, the U.S. produces about 35 million tons of “containerboard,” or the cardboard used to make shipping containers like Amazon boxes. I estimate that at least 10% of that makes it into my home. And while I’m very diligent about recycling all of that cardboard (the American Forest and Paper Association estimates the “effective recycling rate” of cardboard at 85% — yay!), breaking down those boxes to make them ready for pickup is a pain in the ass.

Or so it was until I discovered the Canary utility knife, a thin little knife with a non-stick blade and a bright yellow handle.

Corrugated Cardboard Cutter CANARY, Made in Japan, Yellow

$7.90 on Amazon

$8.40 Save $0.50

$7.90 on Amazon

$8.40 Save $0.50

A stationery knife made by a former Japanese sword company.

This $8 knife—yes, it’s sold on Amazon, though mine came in a padded envelope rather than a box—is made in Japan by Hasegawa Cutlery , which got its start nearly 100 years ago polishing and sharpening swords (the “Cutlery” part was added to the name after World War II, when the company first began making scissors ). Hasegawa’s marketing language implies that the company has applied all of its Japanese swordmaking expertise to consumer products. And while I’ve never tried to smash through a stack of shipping boxes with a sword, I can’t imagine it would be much easier than using my Canary.

My previous methods of cutting cardboard—kitchen scissors or a steak knife (don’t be like me, kids!)—were ineffective, and box cutters, while certainly better, aren’t very good at the job either. Cardboard is tough and fibrous, so a razor blade can cut through it fairly easily, but it’s difficult to make a controlled cut because the blade will veer off course if you try to go against the grain, so to speak; box cutters also dull quickly, but are still sharp enough to easily cut yourself if mishandled.

On the other hand, the Canary’s serrated edges, which run all the way around, cut through cardboard like butter, whether you’re moving with or against the grain, pushing or pulling the blade, or using a sawing motion; its blade stays sharp much longer, and you’ll be much less likely to get cut. (These qualities have made the Canary a favorite among cardboard crafters.)

What do you think at the moment?

I’m not a crafty person, but I’ve used my Canary on boxes both small and large. In about a minute, I cut through the large box my dehumidifier came in, leaving a neat stack of small cardboard pieces that are easy to tie up for recycling. The knife works equally well on lightweight cardboard boxes, like the ones you can buy on Amazon, as it does on thicker ones, like the heavy-duty boxes my Target furniture came in.

Calling this little blade a life-changer would be a stretch, but it has definitely saved me a ton of time—far more than the $8 it cost me.

Looking for something different? Retailers like Walmart, Best Buy, and Home Depot are running Prime Day sales that are especially helpful if you don’t have an Amazon Prime subscription.

Walmart’s Prime Day sale starts at midnight on July 8 and includes discounts of up to 50% . It’s an especially great deal for those with a Walmart+ subscription.
Best Buy’s Prime Day sale , Black Friday in July, runs through Sunday, July 13, and is one of the best tech deals online . It’s an especially good deal for My Best Buy Plus or Total members.