Is the wig double or single knotted?
We work hard to understand what the customer is really asking for, instead of relying on the accuracy of the terminology the customer uses. This is because, often, a client who has researched lace wigs online, has found the wrong terminology to describe what they want. Consequently, we ask them to describe the end result, not focus on the terminology.
Getting to the answer...
As a standard, we don't double knot the hair on our wigs. Most people want the smallest knots possible, and double knots are actually knotted twice, which makes the knot larger, and nearly impossible to bleach. What we have found, is that most people who ask about double knots aren't actually asking about double knots, they are asking if we use single strand ventilation vs multi-strand ventilation. In other words, how many hairs are in each knot.
Generally speaking, along the front hairline and first few inches of a wig, we use single strand ventilation, one hair per knot. Once we get into the crown, there are often 2 hairs per knot, and towards the back there can be 2-3 hairs per knot. There are a variety of other ventilation techniques used, but this is just a basic explanation. In medium-heavy and heavy density wigs, there may be 4 hairs per knot to meet the density requirement. When there is more than one hair per knot, that is called multi strand ventilation.