What happens to the pigment when it is implanted in the skin?

When researching for an article I was writing for the the permanent cosmetic industry, I found an article that was quite interesting. It is written for the medical community related to a specific area of cosmetic tattooing, but the basis of what happens to the pigment after it is implanted in the skin.

Unlike many works of art, I work on a living canvas. It changes constantly. Your body is constantly working with the pigment I implant. Please read this very interesting description. All photos have been removed from the content.

Excerpt from:

Scalp Micropigmentation A Concealer for Hair and Scalp Deformities

WILLIAM R. RASSMAN, MD; a JAE P. PAK, MD; b JINO KIM, MD; c NORMAN F. ESTRIN, PhD

PHYSIOLOGY AND HISTOLOGY OF PIGMENTS IN THE SKIN

"Once the pigment is placed into the scalp, the amount of pigment that remains over the first few days reflects the quantity and depth of placement. The epidermis ranges in thickness between 0.5 to 1.5mm. Both the stratum corneum and stratum granulosum, constitute the primary barriers for the protection of the skin. The largest layer in the epidermis is the stratum spinosum, and this area fills with pigment in the track created by the needle(s). The deepest layer of the epidermis is the stratum basale, a row of columnar cells resting on the basal lamina that separates the epidermis. Redness which appears on day of procedure and disappears in 1 to 2 days. These cells are mitotically active and they migrate upward toward the surface. The authors try to limit the depth of the needle(s) to the upper dermis. Significant amounts of pigment may be found in the basal cell layer immediately after the process is done. Pigment particles are found within the cytoplasm of both keratinocytes and phagocytic cells, including fibroblasts, macrophages, and mast cells. At one month, the basement membrane is reforming, and aggregates of pigment particles that are present within the stratum basale are starting to disappear, as these cells migrate upward toward the surface. In the dermis, phagocytic cells that contain pigment may concentrate along the epidermal-dermal border below a layer of granulation tissue that is closely surrounded by collagen. The cells of the stratum granulosum and the stratum spinosum contain particles of pigment, as they migrate upward. eventually, all of the pigments found in the epidermis will be pushed upward with the exfoliation of the stratum corneum. The only pigment that will remain will be the pigment originally placed in the dermis. This represents a satisfactory outcome. The portion of ink that washes away on the patient’s first hair wash (2–3 days) reflects the pigment on the surface of the scalp or from the needle track within the stratum corneum and stratum granulosum. With the normal stratum corneum turnover of ~27 days, it is likely that the pigment remains below the stratum corneum in the lower layers of the epidermis for a few months. How much of the pigment remains in the stratum basale and how long it stays there probably varies in different people, especially those with skin diseases that impact skin cycling. eventually, all of the epidermis becomes free of pigments. The depth of the stratum basale from the surface of the skin varies significantly along the skin, millimeter by millimeter, reflecting an undulating depth of the epidermis at the dermal border. This makes the depth control by an operator who manually controls the needle by the feel of the resistance