The big difference in a lace frontal and a closure is the construction, the materials used, and how they are applied.
In GENERAL a closure piece is usually used for sew in installs/applications. If placed properly just behind the hairline, it can allow the wearer to wear a full weave with no hair left out while giving the appearance of a natural scalp area.
Closures do not run temple to temple. Instead they are placed in the horseshoe area at the top of a weave to close off the style. (Hence the name closure)
The most popular breathable closures are constructed from silk mesh with a poly strip or thin skin around the outer perimeter of the mesh which strengthens the mesh (for a sewn-in application) or to make bonding the closure easier. These closures allow for freestyle parting along the cap area. The addition of a flesh colored stocking under will help to add the look of a natural scalp to this style of closures. This type of closure may require the sealing of the knots (as in a lace frontal) to help keep the hair secured firmly in the base.
Some vendors also construct closures from lace similar to or slightly heavier than a lace frontal. Lace based closures are installed like other closures, but may not look as natural when parted as they will tent to have a grid like appearance in contrast to the braided foundation they are installed on top of.
A few vendors use a combination of stretch lace and flesh colored French silk to create a breathable closure which looks like natural skin. The skin can be dyed to match the wearers own natural skin.
While not nearly as popular these days, some vendors continue to manufacture and sell non breathable closures. These closures are usually a silk mesh top with a full flesh colored poly coating or full flesh colored vinyl skin top (which was once popular in older style wigs)
In GENERAL a lacefrontal is meant to be bonded in place. Like a lacefront wig, a lacefrontal piece has a realistic hairline which is meant to mimic hair growing from the scalp. When bonded along the hairline correctly, they achieve just this affect.
Lacefrontals cover a larger area than closure as they will have a temple to temple hairline. This larger temple to temple area in combination with the replication of a natural hairline allows for many off the face type of hairstyles that are not possible with a regular closure. Just like its full sized lacefront wig counterparts, a frontal will require the sealing of the knots to help keep the hair secured firmly in the cap.
How is it installed??
Closures can be installed by bonding, as well as by attaching with the use of clips. The most popular method for installing closures is by sewing the closure then installing the rest of the weave around the closure. The closure is placed close to the edge of the braided foundation near the hair line.. The stylist then sews around the perimeter of the closure taking acre to stitch so that the stitches are concealed..
Depending on the desired finished style, some of the wearers own natural hair may or may not be left out near the perimeter of the front edge of the closure to help conceal the front edge.
Like a closure, lace frontals can be sewn in place or applied using clips. However a natural hairline will not be achieved if sewn or clipped in the front. Most stylists install a lacefrontal using clips or by sewing down the back of the frontal and use a bonding agent to glue the front hairline down.
Unlike a closure, none of the wearers own hair will be left out in a bonded lace frontal installation as the piece is meant to create a natural hairline.