Hmm...how to explain, how to explain...
UmmHow can I paint on a layer with the paintbrush tool, with opacity less than 100%, so that if I go over the same area more than once it will no darken or alter in any way...and I can use a different colour but it will only add the new colour to the areas that I have not already painted...make sense? Cant explain any better. I know its possible because I was doing it just yesterday!

Hi Grim, LTNS (long time no see)

What you need to do is set the lowered opacity on the LAYER and not the BRUSH. This gives you the same effect (ie: red @ 45% = pink) and a solid colour. Your only concern may be in the layer order and its effect on your painting.

hopefully this is what you're looking for...

if not let me know, i am an ignorant SOD sometimes ;)

later,
:)
scott

If I get your meaning right. Make a new layer and select your paint brush. In the brush options (on top) lower your opacity and make sure your airbrush is turned off. The airbrush setting will darken the area with each pass of the brush.

I was too slow but different method

I'm SHOCKED i actually beat you (though my method may not work for him the way he want's so it may be worthless blather...)

;)
scott

And mine might work for him lol

hmm...I'm not sure if that's what I mean. I'll go and try and get back to yawl. It's confuserating to explainerate these things sometimes.

This example shows what I DO NOT WANT TO HAPPEN. See the overlapping of the two colours which make a third colour? The Layer is set at 50% opacity and the brush is set to Darken in the example. Yesterday, I was able to paint different colours on the SAME LAYER, side by side, without having to worry about overlapping. I could be as sloppy as I wanted, and the paint would only go into unpainted areas. It had something do with layer settings and brush settings, I just cant remember the combination.guess it wasnt such a basic thing afterall!

Grimtwist, I think it might be a blend mode choice. If you choose the blend mode Behind from the Option bar like Dreamer101 mentioned this may give you the effect you are looking for. I use this when working on the same layer with a different color.

YO

Grimtwist, if you dont want any overlapping of colors then you could create a mask on the lower layer that masks all areas that the upper layer has color on. That would still give you the 50% color fill on each layer but would not let those two colors blend into a third color. Have fun, Enian

I think you want to set the brush mode to "Behind" and make sure that lock transparent pixels for the layer is not enabled (must be a layer, not the background).