Ekade, when you’re working on “virgin hairs”. It is considered virgin, an area that has never been touched, or when it has been more than 8 months since the last hair removal with any temporary system. As I said, when you’re working on these hairs, all follicles have a similar depth, because there are many in the telogen phase, very, very few in catagen, and some more in late anagen. The root of a late anagen hair has almost reached the level of the permanent zone, ie the “erector pili”, the location of the bulge. On virgin hairs, I almost never see hairs in early anagen, but probably there a 1 or 2 ‰ in this phase at any given time. I tell you this so you understand the difference in the depth of insertion is just 1 mm or 1.5. No more. Therefore, a single pulse was enough to kill all the hairs in all phases.
Hey Josefa, I just wanted to make sure. When you say temporary system does that include non-depilatory hair removal like shaving?
Thank you again for your reply, Josefa!
It was surprising to hear about 8 months though. I thought that 3 months is enough for body hairs to be in telogen.
Why should it?
Shaving, be it mechanical or chemical, or trimming will just remove the tip of the hair. The region of growth is not affected at all.
Hey Josefa, I just wanted to make sure. When you say temporary system does that include non-depilatory hair removal like shaving? [/quote]
Except bleaching and cutting with scissors, everything else will put obstacles to achieve our main goal: eliminate as many hairs as possible in the first clearance.
Why should it?
Shaving, be it mechanical or chemical, or trimming will just remove the tip of the hair. The region of growth is not affected at all. [/quote]
Ah good. I remember now what mrs. Josefa said before. Shaving was about the length, so that it wouldn’t be too short for electrolysis.
Anyway when I get my first treatment it will have been almost 2 years since waxing some areas, and 1 year on some areas. So I hope I did it correctly.
Johnson, if you shave, telogen hairs can not be removed.
Look what happens:
Thanks for the link. I will only cut shorther with scissors, and the last few weeks before treatment I won’t even touch them.
In order to avoid possible problems with the language a quick summary of the effect - telogen hairs grow slower than anagen ones or even almost stopped growing. If You shave, they might become too short (that’s why i am hunting for all those tiny telogen stubbles i can see a 6X magnification). Chemical removal is even more critical because the destruction reaches into the follicle.
Thanks Bea, you’ve made it very clear. 
The problem of shaving is that the client confuses true regrowth with false regrowth. A clue to interpret the results: after a first clearance, in which telogen hairs remain flush with skin, the view is that the area has been cleaned, but when you touch you can still feel the hairs that puncture, the skin is not smooth !
And if the hairs are grown much longer does that allow you to work faster? The longer the better?
Different collegues seem to have slightly different preferences regarding hair length. I prefer if the hairs are not too long but of course can treat hair of any lenth including most of the tiny telogen stubbles.
My preference is 1-3 millimeters in length.
This preference is for all areas of the body, or is it just for the face, David?
This is my preference for the face. I prefer body hair to be slightly longer since the angle of growth can be greater than 45 degrees.
I find longer hairs much more difficult to work with, the longer hairs can distort the view of the direction of the follicle. Ideally I prefer 2 to 4 mm.
I also find longer hair situations tricky. The game pick up sticks springs to mind. Where untreated hairs pass over and under treated hairs it can be difficult to tweeze away treated hairs. Josefas use of her fingers and treating multiple follicles seems to be the only way to practically work long hair scenarios and keep any kind of speed.
Interesting replies, so most prefer shorter. Since I will be treated by Josefa I would like to ask her too. What hair length works best for you? 
Like Michael, I celebrate being in front of a case of “virgin hairs”, ie, the maximum they can achieve.
The angle of insertion is not a problem for me if the hairs are very long.
I have scanned and prepared for e-mail, a copy of the study Dr. Kligman of Brown University did with Lucy Peters " Histologic Changes of Human Hair Follicles After Electrolysis: A Comparison of Two Methods" This was published in Cutis in the 80’s
Anyone that would like a copy, PM me here or e-mail me through laurierinstruments.com and give me the address you’d like it sent to. It’s a rather large file since 4 of the pages contain microphotographs and had to be scanned in color. Total of 3.2mb, 9 printable jpeg images.