The second most common cap construction is the “Monofilament-Top.” This is a wefted wig that features an inset of transparent micro-mesh sewn in at the crown, with the individual strands of synthetic fibre or human hair hand-tied into the mesh. Mono-top wigs are generally more natural-looking, as the hair appears to be growing out of a real scalp.

This type of cap was first developed for women who had experienced significant hair loss due to chemotherapy, alopecia, or other medical reasons, as the transparent mesh allowed the bare scalp to show through. You may sometimes see mono-top wigs referred to as "medical wigs" for this reason. However, many women with full heads of hair prefer the mono-top wigs for their superior natural appearance. With a mono-top wig, the hair can be more sharply parted on either side of the head than with a conventional wefted cap wig.

All mono-top wigs feature "tape tabs" on the inside of the cap, usually in 4 or 5 spots. These tabs are made of a shiny plastic material, and allow the wearer to use double-sided tape to secure the wig to the head, if necessary. Generally, mono-top wigs are recognized as a higher quality wig product, and are more expensive than standard wefted cap wigs. A slightly less expensive alternative is a wig featuring a monofilament part, rather than a full monofilament top. These are wigs that have a thin strip of monofilament mesh sewn in just at the left, right, or centre part line. In these cases, the location of the part cannot be changed.

Monofilament wigs online are specially designed for those with severe or total hair loss. Most of their advantages are in comfort, but there are some advantages to their natural styling ease as well. All of the comfort advantages are brought back to square one, if you have a full or average head of hair.