Making a multiple exposure self portrait.

[chris-p]

Yeah, you must be doing something wrong as it should work. Have you checked the blend mode of the brush and layer? They might be the cause. It's still possible that you're not selecting the layer mask - try selecting a white brush and clicking on the layer mask icon in the layers palette next to the hue/adjustment icon on that layer and then try painting in white.

Oh, also check the brush size, flow and opacity - I'm running out of ideas though. You could take a screenshot and upload it so we can see your screen, we might spot something...

[MattUK]

Ok, when you select the layer you want to paint black or White, make sure you select it by clicking the box on the right in he layer palette, not the box on the left.

[Mannananscloak]

Despite your great help which I appreciate very much I'm sorry to say I still have the same problem. I know I must be doing something wrong but for the life of me I just don't know what so here is a screen shot...It's as far as I can get 'cause when I then change my brush to white nothing happens on the layer at all......Sorry!

[rbarry]

In the drop down painting mode box you have selected "Darken". Change this to "Standard".

Let us know if this fixes your problem.

[Mannananscloak]

Thank you all so much for your help with this annoying problem, which I'm glad to say is now fixed. Somehow along the way I must have altered brush settings which affected how they worked so all I had to do was to reset all tools and the way I did this was......On the far left hand top side there is a blue box avatar pse. Directly underneath is an arrow. Click on that and you get an option reset tools or reset all tools...

[chris-p]

Glad it's sorted.

The blend modes can be very useful - people often don't realise (or forget) that they can be applied to brushes and other tools as well as layers.
Darken & lighten are often the most useful as you can mask exposure adjustments in just one direction (darken or lighten) and that can make life much easier!