How do I match existing wall texture?

Ah, matching old texture is so difficult. This texture looks a lot like what is in my current house and was done with what looked like a small cotton mop head, hit against the wall, thus giving a variety of textures. You could try to do this yourself but I recommend practicing the technique first. You might need to do some flattening when the texture is partially dried. There could be some shrinkage of the texture as it dries...but these are items you'll address with practice. When finished, prime, then paint. Good luck!

Awesome thank you

I used joint compound and a sponge. You may have to go over the total surface to get an even looking texture. You can thin it with water if it is too thick. Once it is dry, you can check the finish and sand off any high spots. There is also paint that has a sand finish. If you use it, you can't stop in the middle of a wall or you will have a ridge.

I have tried soooo many times to duplicate texture lie this. I'm pretty good at this stuff and I find this task impossible. For all the hours I have spent trying, I wish I have just started over in the first place. As Judi says, you may have to go over the entire surface. They don't do this texture any more, so who can even guess how they did it. I was told it was done with roller. Now I just go over the entire wall with a thin coat of dry wall mud this an 8" blade in any design I choose and its done in no time. Not only that, it gives the room a whole new fresh look. Good luck!

When “mopping” was mentioned, I thought of you using a BBQ mop. It could work for for areas where you need to blend the texture.

That's done with a crows foot texture brush and well thinned drywall compound ... https://www.google.com/search?newwindow=1&ei=b3ThXJ7YD5DytAW2_KfwDw&q=crows+foot+texture+brush&oq=Crowfosor+texture+brush&gs_l=psy-ab.1.0.35i304i39j0i13j0i8i13i30.36128.36128..39960...0.0..0.83.83.1......0....1..gws-wiz.......0i71.XOi8k_ruiNs