On this video tutorial Aaron Nace from Phlearn demonstrates how to use the brush tool in Photoshop to perfectly cut hair.
Cutting hair is probably one of the most difficult tasks in Photoshop. There are many ways to do this (see below) but on this video Nace uses a custom brush that he creates to cut hair.
Usually it is easier to cut the body out of the background than the hair (although there can be more difficult images where the body/clothing are also pretty hard to cut).
You start by creating a single strand of hair which is just a brush stroke with a very small diameter to simulate a hair. Now select the Rectangular Marquee Tool and create a square selection around the hair by holding SHIFT+CLICK-DRAG. Fill the square selection with white and move it behind the layer with the hair on it. Center the hair in the white square by clicking on the Pen Tool, then the Alignment Controls on the top of the screen.
After the hair is centered, keep the selection of the white square active and go to “Edit – Define Brush Preset” and give the brush a name. Now you need to give this brush its features – to open the Brush Menu, go to “Window – Brush.” In this advanced menu, you can control many characteristics of a brush, including shape dynamics, scattering, rotation and size. For best results, mix and match settings to simulate natural hair. Try adding Size Jitter, Angle Jitter, Scattering, and Roundness Jitter.
Now it is time to paint on the layer mask to reveal the hair. Keep in mind, hair changes size and direction on different areas of the head. The Custom Hair Brush can be rotated in the “Brush Tip Shape” dialog in the “Brush Menu.” Change brush size using the open and close brackets “[” “]”.
Now all the remains is to paint a layer mask with this new brush to help “reveal” the hair (you can show the layer below – go to window-properties and control the density of your layer mask so that you can see the layer behind and see what you are doing). You can also change the direction of the hair as you are going in the brush panel.
This isn’t the first time we look into advanced hair selections in Photoshop. We have looked at how to make fine hair selections many times in the past on several different videos aimed at different levels of photographers/image editors – including “How to Cut Out Complex Hair in Photoshop” with Nace, Photoshop senior product manager Bryan O’Neil Hughes had a very nice simple guide for beginners entitled “How to Make Fine Hair Selections in Photoshop” while both Jesús Ramirez with “Advanced Hair Selection Tutorial – Masking Hair In Photoshop” and Michael Woloszynowicz with “How To Quickly Remove Stray Hairs in Photoshop” had some more in-depth guides.