Few Photoshop problems

[Nic]

On photoshop when i try to draw with a plain brush which is black it comes out grey if i go over it gets darker and darker and darker each time i do it. Ive shut it and reopened it tho and its still doin the same thing...any dieas what it could be?
Also if I try to fill my background with any colour the blank canvas 'twitches' and it comes up in history fil btu it is still white. Any ideas would be apreciated

 

[Waffle]

Chances are for the brush problem either:

Air Brush is selected
Opacity and or fill levels aren't 100%
The brushes blending mode isn't "normal"


And the same for the fill - check the blending option is on Normal, not anything else.

 

[Nic]

Thanks for that waffle it was both the opacity...i shud remember to check simple things. Thanks again