"It's" in my sentence

[Rachel Adams]

This is my answer to the question "Do you prefer using water colors or oil paint?" Can I use "its" in my response?
http://iteslj.org/questions/art.html
"I sometimes use watercolors and sometimes oil paint. I prefer watercolours. It's better."

 

[Charlie Bernstein]

This is my answer to the question "Do you prefer using watercolors or oil paint?" Can I use "its" in my response?
http://iteslj.org/questions/art.html
"I sometimes use watercolors and sometimes oil paint. I prefer watercolours. It's better."

You'll probably get a few different answers to this. I'd use They're, but some might treat watercolors as a singular noun.

I think it's better to pluralize both or neither: oil paint/watercolor or oil paints/watercolors.

Let's see what others say.

You used both the American watercolors and British watercolours. Do you usually use British or American English? Use one or the other, not both.

 

[Yankee]

This is my answer to the question "Do you prefer using water colors or oil paint?" Can I use "its" in my response? Yes, for a category.
http://iteslj.org/questions/art.html
"I sometimes use watercolors and sometimes oil paint. I prefer watercolours. It's better."

Y.

 

[Rachel Adams]

You used both the American watercolors and British watercolours. Do you usually use British or American English? Use one or the other, not both.

BrE. OK. Thank you.

 

[Charlie Bernstein]

BrE. OK. Thank you.

You're welcome!

As I say, just be consistent. British or American English. Singular or plural. Don't mix.