Software
Hair Strand Designer
Robert Ramsay has released a low-cost app for designing game-ready hair strand texture maps that can be used to texture hair cards. According to the developer "it produces an RGB Masking system for Color Variation, Root Mask and Tip Mask. It also produces a Color Map, Normal Map, Depth Map, ID Map and Mask Map. You have control of waviness, tapering, scale, variation, colouring, spacing, thickness, length and number of strands in 8 possible sets". You can get software for $5 and read more about it on Artstation.