Flying - Emergency Help Needed!

Malcolm,

(Answering on Joshua's behalf...)

Add a layer mask to the copied top layer (click the grey rectangle with circle inside on the layers palette). Click on the layer mask in the layers palette so you are painting on the mask, and not the image itself (otherwise you are going to get black and white splodges )

The layer mask only allows greyscale. You can then paint black and white to allow and disallow the layer to show through. I find that selecting a lower opacity (like 50%) is helpful so you can blend the effect in really naturally. Black on the mask hides that layer (thus showing the underlying layer through).

If you need to see what the mask looks like, hold Alt down and click the mask - you'll see just the mask in black and white. Incidentally, all the filters can be applied to the mask itself (like gaussian blur etc), as well as copy and paste etc.

It's also useful to use the magic wand to select areas of colour from the image, move to the layer mask, then delete the selection - a great way of quickly producing a mask.

It's a great technique, definitely worth mastering
Enjoy!
Matt

When you add a layer mask to the top layer you can use the paint brush set to black and paint on the layer mask. It won't cover it with black but will instead "erase" the top layer or reveal the layer under it. Painting back over it with white will bring back the top layer.
Just make sure that when doing this painting you have selected the layer mask and not just the layer.