Learn English – What does ‘the’ in ‘the someone’ mean

My answer is semantic, not grammatical. The issue is one of meaning, not of rules of syntax.

If you intend that there is one unique correct answer then "the right answer" is the correct meaning since the noun "answer" is fully determined by the adjective "right".

Similarly, there are usually many incorrect answers: so "That's a wrong answer" is correct and meaningful. You are wrong to say that this is not grammatical. Similarly, you can use "the perfect car" to imply that the car is fully determined by its perfection, but you can also use "a perfect car" to imply that there are others that are equally good.

So in all the examples you give, both "a" and "the" are grammatically possible. A native speaker would intuitively choose an article according to the meaning that they want to give.

Generally, adjectives that are incomparable will be more determining. If you can't be "righter" or "less right", then a noun will be fully determined by the adjective and so the article chosen will be "the".

It depends what you're trying to say:

• "Khokhloma painting" (with no article) would be the name of the technique itself, e.g. "She is a master of Khokhloma painting"
• "a Khokhloma painting" (indefinite article) would refer to some unspecified example of the technique, e.g. "While I was there I bought a Khokhloma painting"
• "the Khokhloma painting" (definite article) would refer to a specific example mentioned elsewhere, e.g. "The Khokhloma painting which I bought was beautiful"
• "the Khokhloma painting" would also be used if there was exactly one such painting in the whole world, rather than a technique, in the same way as the Bayeux Tapestry

There are also two relevant meanings of painting:

• The concrete noun (used with an article) is used specifically for flat artworks, typically on canvas, paper, or similar material; the kind which you would put in a frame and hang on the wall.
• The technique (used without an article) can also refer to any decoration with paint - for instance, decorating pots, or houses. In that case, it generally refers to the process, whereas the result might be "paintwork" - so you might say "The Khokhloma paintwork on this pot is very beautiful" (again, using the definite article to refer to a specific example).

Finally, note that the same rules apply to any adjective used in the same way, not just one which comes from a proper name. For instance:

Claude Monet was a master of impressionist painting.
An impressionist painting by Claude Monet was sold recently.
The impressionist painting which was sold fetched a high price.