Style, artist and ink quality matter. Placement matters more than all three combined, and it is the only one of the four that is decided before anything is drawn.
Three things, and none of them is time by itself.
Ultraviolet light. The single biggest factor, ahead of everything else combined. UV breaks down pigment particles in the dermis and the immune system carries the fragments away. A forearm that has seen twenty summers unprotected is a different tattoo from the same piece on a thigh.
Friction. Waistbands, watch straps, shoes, the inside of an arm against a body. Abrasion thins the epidermis above the ink and the immune response underneath never quite settles.
Cell turnover. Skin replaces itself at different rates in different places. Palms, soles and fingers are the fastest on the body, which is why ink there breaks up in years rather than decades regardless of who put it in.
Everything below is those three, applied to a map.
The best surface on the body and it is not close. Flat, low friction, easy to keep covered, and skin that turns over at an ordinary rate. A well-drawn piece here at twenty years still reads exactly as intended.
Nearly as good and usually better protected from sun. Large, stable, low friction. The obvious answer for a big piece somebody wants to keep.
Stable skin, big surface, and out of the sun for most of most lives. The classic placement for large work for good reasons.
Good, with an asterisk shaped like summer. Sun exposure is the only real threat and sunscreen genuinely solves it.
Thin skin over bone, considerable movement, and the ink sits shallower relative to the surface. Fine at scale with weight in the drawing; poor for fine detail.
Constant flexion and skin that rubs against the body. Softens noticeably faster than the outer arm two inches away.
Shoes, friction, and skin that turns over quickly. Almost always needs work inside five years.
The fastest turnover on the body, plus constant abrasion and washing. Broken up inside two to three years, reliably. This is why we decline it.
A tattoo has to be legible at the distance it will be seen from, which for most placements is about six feet. That sounds obvious and it is the thing most references get wrong, because the reference is a photograph taken from eight inches away in perfect light on week two.
The practical rule your artist is applying: anything under about three millimetres between two elements will close up eventually. So a design that needs those gaps needs to be bigger, or needs fewer elements. Those are the only two options and the second is usually the better drawing.
It can restore saturation. Colour that has lightened and black that has gone grey take ink again, and a session at year twelve can bring a piece most of the way back to how it healed.
It cannot un-spread a line. Once two lines have closed into one, going back over them adds more material to a place that already had too much. That is why the design decision at year zero matters more than any maintenance decision later, and why we draw with gaps that look slightly generous on the day.
Sunscreen, after week six, forever. It is not a small effect at the margin. It is the difference between a fifteen-year tattoo and a thirty-year one, on the same skin, from the same session.
Ultraviolet light, ahead of everything else combined. Then friction, then skin turnover rate. Placement decides all three, which is why it matters more than style, artist or ink.
Inner forearm, outer thigh and upper back. Flat, low-friction, ordinary turnover, easy to keep out of the sun. Twenty years and still legible.
Fingers, palms and soles have the fastest cell turnover on the body plus constant abrasion and washing. They break up in two to three years regardless of who applied them.
Saturation can be restored: lightened colour and greyed black take ink again. Spread cannot be undone, which is why a design needs gaps built in from day one.
Bring the idea and let the consult argue about where it goes. That conversation is worth more than the reference.
Example interactive prototype. Not a real business. Names, photographs, reviews and figures on this page are illustrative. Identifying details on real client work are changed to protect their privacy. This is what Yeti can build for a tattoo studio in seven days.