Unless you separate each hair, 6 barbs will pick up 6 hairs if you root from the end or 12 hairs if you root in the middle, the bigger the needle the more hairs will pick up per barb more since the barbs are bigger.
I separate the hairs when I use a multi barb needle it’s more precise, and less time is used going back with tweezers. But with the 43g single barb it has one little barb and usually picks up one hair, I LOVE it. I don’t use a tool and hold the needle so I can feel what’s going on. If you pullback ever slightly before you insert the needle, you can just feel the hair catch in the barb and then you insert the needle/hair in the head, usually only one hair goes in. If you root in the middle it would look like 2 hairs coming out of each hole. If it’s around the face I will root the end separating the hairs, but for the back of the head I root in the middle. I normally root by touch when I’m watching TV, lol. Funny I can root with a sharp needle without looking, but as a child, even with 3 years lessons I could never play the piano.
No matter what anyone says, every one started at the beginning and broke a bunch of needles. When I started I was a lot slower and broke 10+ needles a head. No need to pay for “Reborning College”, you can also find all you need to know on youtube with Nikki Holland from Still Moments Nursery. She’s a top reborner in Australia and shares all her secrets http://www.youtube.com/user/stillmomentsnursery#g/u or her website http://www.stillmomentsnursery.com/store/ I learned most of my stuff from her videos, for free. Nor should you pay $40 an ounce for mohair to be a good rooter, I buy the same washed “wool fiber” for $10 a POUND and dye it with $3.75 wool dye(no human hair dye or RIT clothing dye). You have to have a combo of knowledge an natural talent, advancing out of being a hobby reborner to making a doll that someone would pay for and you can be proud of. Trust me I have a few dolls fully wrapped in their receiving blankets hiding in my closet, one day I may fix at them.