Liquid eye liner is an opaque liquid that usually comes in a small bottle and is typically applied with a small sharp-tipped brush. It creates a clean, precise line. Because liquid eye liner gives a much heavier appearance, it is often only applied to the upper lash-line.
Powder-based eye pencil is eye liner in a wood pencil. It is generally available in dark, matted shades.
Wax-based eye pencils are softer pencils and contain waxes that ease application. They come in a wide variety of intense colours as well as paler shades such as white or beige. Wax-based eye liners can also come in a cone or a compact with brush applicator.
Kohl eye liner is a soft powder available in dark matte shades. It is most often used in black to outline the eyes. It comes in pencil, pressed powder, or loose powder form. This type of eye liner is more likely to smudge.
Gel eye liner, which is a softer gel liner, that can be easily applied with an eye liner brush. It can be precisely applied and is much softer than Kohl.