על תווית העור כתוב ניקוי יבש.

Literally, כתוב means written. In context, though, English usually translates it as it says.

Hebrew very often uses כתוב for words that appear on something written, such as a sign, label, page, or notice. So this sentence is literally something like:

On the leather label, dry cleaning is written.

But the natural English sense is:

The leather label says dry clean.

Because תווית is not the thing that is written.

The thing being written is ניקוי יבש, and the head noun there is ניקוי, which is masculine singular. So כתוב agrees with that idea, not with תווית.

You can think of the sentence in a more transparent order like this:

ניקוי יבש כתוב על תווית העור
Dry cleaning is written on the leather label.

So כתוב is masculine singular because ניקוי is masculine singular.

Because תווית העור is a construct chain (סמיכות), a very common Hebrew noun pattern.

In a construct chain:

• the first noun usually does not take ה־
• definiteness is shown on the last noun

So:

• תווית עור = a leather label
• תווית העור = the leather label

That is why you see תווית and not התווית here.

Also, this is not because of על. The preposition על does not absorb the definite article. If the phrase were simply on the label, it would be על התווית.

It can mean either skin or leather. Hebrew uses the same word, עור, for both.

Context tells you which one is meant. In clothing, accessories, and care labels, it very often means leather. So here העור is naturally understood as the leather.

It is a noun + adjective phrase:

• ניקוי = cleaning
• יבש = dry

So literally it means dry cleaning.

Because ניקוי is masculine singular, the adjective is also masculine singular: יבש.

This is the normal Hebrew term for dry cleaning.

Yes, it functions as an instruction on a care label.

Hebrew labels often use short noun phrases instead of full sentences or imperatives. So ניקוי יבש is a compact label-style way to mean something like:

• dry clean
• dry cleaning only
• requires dry cleaning

So grammatically it is a noun phrase, but functionally it gives a care instruction.

Because Hebrew normally leaves out the present-tense form of to be.

So where English might say:

On the label it is written...

Hebrew can simply say:

על תווית העור כתוב...

This is completely normal Hebrew.

Hebrew word order is more flexible than English word order.

Starting with על תווית העור puts the location first: On the leather label... Then כתוב introduces the written content, and ניקוי יבש comes after it.

A different order such as ניקוי יבש כתוב על תווית העור is also understandable, but the given order sounds natural and common, especially when the speaker wants to begin with where something is written.