Оберни винил бумагой.

Оберни is the informal singular imperative of the verb обернуть.

So it is used when speaking to:

• one person
• in an informal way

It means something like wrap! or cover!

Related forms:

• оберните = formal singular or plural wrap!
• обернуть = infinitive to wrap

Обернуть is a perfective verb, so the command focuses on a completed result: the vinyl should end up wrapped.

In commands, Russian often uses:

• perfective imperative when you want a single completed action
• imperfective imperative when you mean repeated action, process, or general instruction

So:

• Оберни винил бумагой. = Wrap the vinyl in/with paper.
• Оборачивай винил бумагой. = more like Wrap the vinyl with paper (as a process / regularly / keep doing it).

Here винил is the direct object, so it is in the accusative case.

But винил is an inanimate masculine noun, and for many such nouns, the accusative singular looks exactly like the nominative singular.

So:

• nominative: винил
• accusative: винил

That is why the form does not visibly change.

Бумагой is the instrumental singular of бумага.

Russian often uses the instrumental to show the material, means, or covering substance used to do something.

So in Оберни винил бумагой, бумагой means:

• with paper
• using paper
• covered in paper

Forms:

• nominative: бумага
• instrumental: бумагой

This is a very common pattern:

• накрыть стол скатертью = cover the table with a tablecloth
• обвязать коробку лентой = tie the box with a ribbon
• обернуть подарок бумагой = wrap the gift with paper

Yes, Russian can also use a construction with a preposition, but the nuance is a little different.

Compare:

• обернуть винил бумагой = wrap the vinyl with paper
• завернуть винил в бумагу = wrap the vinyl in paper

Both are natural in many contexts. Very roughly:

• instrumental emphasizes the material used
• в + accusative emphasizes what something is being put into or wrapped in

With обернуть, бумагой is very normal. With завернуть, в бумагу is also very common.

Винил can mean different things depending on context, for example:

• vinyl as a material
• a vinyl record
• more generally, music on vinyl

So this sentence could mean different things in real life:

• wrap the vinyl material with paper
• wrap the vinyl record in paper

Grammar alone does not tell you which one is meant; the situation does.

You would use оберните instead of оберни:

• Оберни винил бумагой. = informal, to one person
• Оберните винил бумагой. = formal to one person, or to more than one person

The rest of the sentence stays the same.

The neutral word order is:

Оберни винил бумагой.

This is very natural for a command:

1. verb
2. object
3. material/instrument

Russian word order is flexible, though, so you could change it for emphasis:

• Винил оберни бумагой. = it is the vinyl, not something else, that should be wrapped
• Бумагой оберни винил. = emphasis on paper

But the original order is the most straightforward and neutral.

The stress is:

оберни́ вини́л бумаго́й

A rough pronunciation guide:

• оберни́ = ah-bir-NEE
• вини́л = vee-neeL
• бумаго́й = boo-ma-GOY

Stress is important in Russian, because it is not marked in normal writing but can affect pronunciation a lot.

They are close, but not always identical.

• обернуть often suggests wrapping around / covering
• завернуть often suggests wrapping up something, especially into paper or another covering

In many everyday situations, both can work:

• обернуть подарок бумагой
• завернуть подарок в бумагу

But the exact choice depends on habit, style, and nuance. For a learner, it is useful to remember:

• обернуть что чем = wrap something with something
• завернуть что во что = wrap something in something