Stop tracing loose hair with the Pen tool. Duplicate whichever RGB channel has the strongest contrast, stretch the black and white apart with Levels, clean up the specks with the Brush, then load the result as a selection and the flyaway strands come out precisely. In an online PS it's far quicker than drawing them one by one.
①
Pick a good channel first
Open your image and head straight to the Channels panel (can't find it? just tick it in the Window menu). See the red, green and blue channels? Click through all three and find the one with the biggest contrast between hair and background. Usually that's Blue or Green, because Red tends to blend into skin tones. In my image the background is grayish, and the Blue channel gives the darkest hair against the brightest background, so that's the one. When I was starting out I painted straight onto the original channel and then couldn't undo it… lesson learned the hard way: always duplicate the channel with a right-click first!!
Open your image and head straight to the Channels panel (can't find it? just tick it in the Window menu). See the red, green and blue channels? Click through all three and find the one with the biggest contrast between hair and background. Usually that's Blue or Green, because Red tends to blend into skin tones. In my image the background is grayish, and the Blue channel gives the darkest hair against the brightest background, so that's the one. When I was starting out I painted straight onto the original channel and then couldn't undo it… lesson learned the hard way: always duplicate the channel with a right-click first!!
②
Build contrast so the hair stands out
Select the duplicated channel (it's usually named something like Blue copy) and press
Select the duplicated channel (it's usually named something like Blue copy) and press
Ctrl+L for Levels, or use Curves if you prefer. Drag the black slider to the right to make the hair blacker, and the white slider to the left to make the background whiter, until hair and background split cleanly into black and white. Don't worry about what the skin tone turns into — we only care about those few pixels along the edge.
Don't push it too hard. If jaggies appear along the hair edge, the selection later on will come out rough. A smooth gray band sitting between hair and background is exactly right.
③
Patch it up: white where it should be white, black where it should be black
By now the image is probably a patchwork of black and white, and not clean enough. Take the Brush tool at 100% opacity and 100% flow and paint the model's body and face pure white (start with white on the interior, and be careful not to paint over the hair edge). If the background has white specks, switch to black and cover them. Don't get too fussy — the gray-and-white texture along the hair edge has to stay, because that's the detail of the strands.
By now the image is probably a patchwork of black and white, and not clean enough. Take the Brush tool at 100% opacity and 100% flow and paint the model's body and face pure white (start with white on the interior, and be careful not to paint over the hair edge). If the background has white specks, switch to black and cover them. Don't get too fussy — the gray-and-white texture along the hair edge has to stay, because that's the detail of the strands.
④
Load the selection and go back to the layers
Hold
Hold
Ctrl and click the thumbnail of the channel you just duplicated (the little square), and the marching ants will appear. Click back onto the RGB composite channel (the top one), then switch to the Layers panel. The selection now traces the figure. Press Ctrl+J to copy the selection onto a new layer, and you're done. The background disappears and every single strand stays.
A few parting thoughts and pitfalls:
• If the background is light and the hair is dark, step ② works the other way round: pull the hair black and the background white. Same operation.
• If the selection comes out with a white fringe, use Layer menu → Matting → Defringe and set it to 1 pixel; it cleans up a lot.
• If the background is dark and the hair is light (blond hair, for example), you'll need
• Want to try this method quickly without opening a big app? This online PS has all the channel features, it's free and there's nothing to download. It's what I use for emergencies at work.
• If the background is light and the hair is dark, step ② works the other way round: pull the hair black and the background white. Same operation.
• If the selection comes out with a white fringe, use Layer menu → Matting → Defringe and set it to 1 pixel; it cleans up a lot.
• If the background is dark and the hair is light (blond hair, for example), you'll need
Ctrl+Shift+I to invert the selection after loading it.• Want to try this method quickly without opening a big app? This online PS has all the channel features, it's free and there's nothing to download. It's what I use for emergencies at work.
Honestly, the painful part of channel cutout is the painting in step ③, but two runs and you've got it. It's more reliable than the Extract filter and ten times faster than the Pen tool. If you have your own cutout headaches, leave them in the comments and I'll answer what I can. That's all for now — time to eat 😎