How to change pixel opacity

As far as I have understood, there are several places to define the opacity in a layer:
1. In the layer palette, there is a field to set the overall opacity of the layer
2. A layer mask with pixels other than white or black
3. The pixel themselves may have an opacity, e.g. when painted with the airbrush tool

Is there any way to set the opacity to 100% (or any other value)? Number 1 and 2 are easy, but how to deal with the third version? It would be easy to decrease the opacity (by defining and applying a layer mask), but so far I have no idea of how to increase the opacity.

Any ideas what I can do?

I am using PS6.01 on W98SE.

Thanx

Sven

If I understand correctly, you get 100% opacity by using a hard brush with opacity set to 100%. Right?

Colin,

exactly. So creating a new layer would be easy. But I am stuck with an existing one (which is not easy to recreate).

Sven

I'm not sure I understand fully, but I suspect you have a layer which is set to 100% opacity, but that contains pixels which are less than 100% opaque...? (...which you'd like to make 100% opaque...?)

If that's the case, you can duplicate the layer, (or selection), one or more times, and stack them up to "build up" opacity.