There are settings for brightnes and opacity in the layer-properties.

There are sliders to make adjustements to the settings.

 

have a look at this  https://www.dropbox.com/s/tl9fuo3hajrm1zk/test.psp?dl=0

Its vital to know how to work with layers , colorsettings etc. 
This basic knowledge is vital for being able to do good repainting.
The internet is full of instructions about Photoshop and other programs.

 

https://helpx.adobe.com/photoshop/using/layer-basics.html

https://helpx.adobe.com/photoshop/how-to/ps-layers-basics.html

https://wegraphics.net/blog/tutorials/photoshop/photoshop-for-beginners-the-power-of-layers/

 

I'll revisit those links, thanx!

If I select the rivets layer - there is nothing in the properties box and the adjustments are greyed out in the menu. If I select the square icon in the layer, it says mask - there is density & feather in the properties box but no brightness. In the menu - images - adjustments there is a brightness/contrast selection but using those sliders seems to have no effect. I tried creating an adjustment layer immediately above the rivets - moving the slider there also had no effect.

Is there another place to find brightness adjustments? In the paint kit, I'm using the cessna310_ext_01_orig.psd file.

Won't get a chance to get back at it until tomorrow evening but I'll check out those videos.

Thanx for the help.

Vic