Not really, but I highly recommend washing the walls with diluted TSP first, it makes a big difference in how even your next coat will go on in my experience. A few greasy finger marks can show up even three coats later, but if you remove them before you paint, you might only need to do a single coat...

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How about this:

• White flat wall.

• Gyproc has a small dent in it from a hard object bumping into the gyproc.

Do I fill it in with plaster, sand down, prime and then paint over?

Is there a way to make totally invisible, a lot of plaster patches I see are visible not because of size but because you can see the plaster finish being different from the rest of the wall?

Any suggestions are appreciated.

Thanks!

If you have layers of oil or smoke on the walls you might run into problems, I would test the smallest wall and check the next day in bright natural light. With flat you need to paint the entire wall in one go or it leaves lines, just fyi.

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