I’ve had to do this quite a bit.
I’ve used taped on green paper. That usually works quite well. The spill has always been minimal.
Depending on the angle, I’ve shot the hand separately in front of a green screen and at a distance where I can be sure there’s no spill.
I’ve also shot against a black (turned off) monitor. I prefer this method.
I just duplicate the layer, tint it B&W and then really pump up the contrast. I then use this layer as a luma matte. You also benefit from the natural reflections that occur and can composite these over the top via blending modes.
If the shot isn’t locked down or it’s a handheld device, things get a little more complicated with motion tracking, but the principals are the same.
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