I have been asked via email to say how I do my chipped rivets layer. I'm going to answer here though, as the information may be useful to other skinners at some point.
For my chipped rivets layer what I do first is make a copy of my original rivet layer and set it's layer opacity to 100%. Sometimes I have two rivet layers, one for flush and one for raised rivets and in this case I make a copy of both layers, make sure their layer opacities are set to 100%, then merge them together. I name this layer "Chipped rivets" and change the rivets' colour on it to my NMF light grey.
Next I select the eraser tool and set it up the following way:- Tool shape set to square and size to maximum. Hardness is set to 100%, opacity is set to 100% and density to 50%. Then I position this tool so it covers the whole skin and click the left mouse button once. What this does is randomly erase one half of the chipped rivets across the whole skin. If the maximum brush size is less than the size of the skin bmp the solution is to to carefully position and click the eraser tool several times while trying to avoid any overlaps or gaps.
Next I reset the opacity to 50% and click to erase again, which half removes half of the remaining rivets. Then I repeat the process once more but with the opacity set at 25%. The layer opacity can then be reduced to get the level of chipped rivets required.
On a NMF skin there is one more thing I do to this layer. I create copies of all the painted areas layers (anti-glare panels, nose art, air force and unit markings etc.) and merge these into one layer. I then turn everything on this layer pure white with the brightness setting. Next I create a new layer and flood fill it with pure black. Making sure the black layer is below the white one, I merge the two layers. I copy the data from this layer and paste it into a mask layer I attach to the chipped rivets layer. What this mask does is remove all the chipped rivets from the NMF areas of the skin, just leaving them on the painted areas. I find this creating this mask is a big time saver in the long run. It can be used to remove paint chips from the NMF as well and the layers are quick and easy to edit for future NMF skins with different markings.
