Word for a cut in a shampoo packet

Here, I want the word that denotes a cut in a packet of a shampoo. The cut doesn't necessarily be made by those who purchase such shampoos, but by the manufacturers of a particular company. Such cuts are made in packets of shampoos, so that the people who purchase can easily tear them for the use, without even the need of any scissors.

I don't think that the word "cut" would work here, as it usually denotes making an opening, incision, or wound in (something) with a sharp-edged tool or object.

In this image, you can see a [cut] on the upper right side of the packet.

The technical term is indeed a tear notch as mentioned by Lambie

Greener Corporation in Bayville, New Jersey, USA say

A tear notch makes packages produced on vertical form/fill/seal baggers easier to open. This small slit in the end seal allows consumers to easily tear the film in order to gain access to the product.

The slit is produced by a carbide notch punch that is affixed in the sealing face of the jaw. The carbide material provides exceptional durability, and the jaw mounted design provides significant cost benefits when compared to notch punches that are attached to the machine knife.

The tear notch can be located wherever desired on the end seal of the bag and can be integrated with a tear strip feature or “Open Here” graphics.

Greener corporation mentions a slit

slit: a straight, narrow cut or opening in something

however, the Merriam-Webster dictionary describes slit as

a long narrow cut or opening

Notches on packaging are generally small

You could possibly call it a nick

nick: a small notch, groove, or chip

Turpack, a company which manufactures packaging machines advertises nick knives as a feature on their machines. Referring to tear notches, they say

It is a small cut that extends to the adhesive bead in the edge of the disposable packaging. The package is torn, starting from the notch in order to open it. The product is easily emptied from the formed cavity. Foods, medical products and beverages reach the customer extremely simply and quickly with easy open tear notch. Apart from this, we can produce serrated notch and laser notch.

The type of packet shown in the question is known as a sachet.

Alibaba.com advertises a number of them. Larger sachets are called pouches.

Perhaps a perforation:

a small hole or row of small holes punched in a sheet of paper, e.g., of postage stamps, so that a part can be torn off easily.

It's absolutely 100% true that "tear notch" is the industry term.

However it is also absolutely 100% true that no civilian (ie, not in the packaging industry) would refer to it as a "tear notch" per se.

You'd refer to it as the "thing where you tear it open", the "place where you open it" or the "starter thingy for tearing it open" or "the nick thing where you tear it open" or "the thingy where you tear it open" or indeed, perhaps, maybe, the "opening notch" or "nick".

Note. It is very, very, common in English that we don't have a specific word for something, so we call it a "thingy" or a "thingy -term", or just blab about it in a long-winded way using a descriptive phrase.

So understand that with SWRs such as this, very often the correct and real answer is "we don't have a clear, agreed, word for that in English."

(This is such a feature of English, that a handsome/fascinating member of this site once asked as a question, what actually is the term for such constructions:

Term for using "thingy-esque" phrases rather than a common word )

Again in short:

"tear notch" is absolutely the industry term but be aware nobody, at all, ever, would use that exact phrase (outside of the packaging industry).

Be aware that we do NOT have a clear agreed word for that thingy in English (outside of the packaging industry), we would use an ad-hoc multi-word description.

It's an intentionally produced indentation at the edge of the packet. That makes it a notch.

If I wanted to refer to that part of the packet, that's what I would call it: "the notch".