RED BOLE - cast paper, gesso, red bole, 22K gold leaf
a further selection of lips . . . 
                (place your mouse cursor over the image to view the title & materials of each piece)
TUT ET AL - cast and carved dental stone, 22K gold leaf
ALMOST - cast and carved dental stone, gold leaf, paint
BOTTOM'S DREAMING AGAIN - cast and carved plaster, bronze powder, natural patina
One other format in which they are presented is framed under glass.
The framed lips are usually cast in dental stone or hardened plaster, plastic resin, or handmade paper and then the casting is further worked by carving, sanding, or burnishing.
Lips on this page are made in dental stone, cast stone, plaster, plastic resins, ceramic, and paper and then finished a variety of ways.
Many of the lip sculptures are set into wall sculptures using intricate backdrops constructed of stone and other materials,  but they are also presented in other formats.
The works are often finished with gold, silver, brass/bronze, or copper leafing.  After the metal is applied a chemical or natural patina is allowed to develop, and finally a wash of color is applied to deepen the shadows. 
I addition to mounting the metal or ceramic lips on a stone background, another format for presenting the more delicately-finished lips is to frame them under glass. 

They are first mounted in a deep velvet or linen lined shadowbox and then the frame is custom-made -- enclosing it like a specimen of ancient treasure.
MORNING MOUTH: NOT MADE UP YET AGAIN - stoneware, limestone
PUCKERS UP: VERDIGRIS TRIO - cast and carved resin, copper leaf, paint
DREAMS STERLING - stoneware, sterling silver leaf, wood, paint
GREENQUAKE YEARNING: TO THE MOON, SOFIA - cast and carved plaster, metal leaf with chemical patina
LABIUM SPIRITUS EXALTUS - cast paper
MECCANIKA RED - sandblasted cast stone
PINWALE LITTLE PUCKER - cast and carved dental stone, gold leaf, paint
TORN UP - cast and painted paper
Don Dougan - sculptor
                                     www.dondougan.com
Though there is an element of eroticism within all of my lipwork series, there are some examples wherein the sensuality becomes more explicit.  For a sampling of those works please follow this link.
If you feel explicit imagery might not be suitable for your eyes, do not enter.