Here's a short clip I made of me ventilating hair. This is single strand, double knot ventilation using a no. 2 German needle on the lace from Amazing Hair store.
I'm usually a bit quicker than this, but I was working at an odd angle to avoid the camera. Also, I usually work with a magnifier, but was unable to do so here. Unfortunately the old eyes aren't quite as sharp as they used to be!