A masking problem

[greyscale]

When I use channel masking to put a person into a new background I always see a fringe around the edge, especially the hair, of the background colour I moved the person from. How can I stop the edges carrying over pixels from the previous background colour?

[Der_W]

You can either mask more precisely or duplicate the layer and "Multiply" it on the new background (mask out non-hair areas) or adjust the color and brightness of the hair with a new layer as a clipping group set to "Color" or "Soft Light" where you change the color (the stamp tool works pretty neat for that kind of thing) or dodge & burn the hairs.

[mistermonday]

There are many things you can do to solve the problem. Things to try are: Layer>Matting>Defringe - in some cases Remove Black or Remove White edge.
You can also expand or choke the mask using Filter>other> Maximum or Minimum.
You can add a blank layer above the image set to color blend mode and paint around the edge of the hair with the new background color.
You can use Select>Refine Edge.
The list goes on. It might be best if you attached a sample image for people to see and offer specific advice.
Regards, Murray

[greyscale]

Thanks for these responses, I apologise for not responding sooner. I've tried both your suggestions and they have worked well, I'm still a very green novice and your tips have made life easier. I was trying to move blond-haired model Caprice from a bright blue background to a dark red, just as a project, and the blue background was showing through her hair and stuck to her, I want to try the extract tool next, never used it before but I'm wading through Deke McClelland's Channels and Masks series and I've just reached the extract tool movie so here goes! Thanks again.
Greyscale