What makes it fine line
Fine line work uses a single needle or a small grouping for thin, even lines, with little or no solid fill. It suits botanicals, small symbols, script and outlines of animals.
It is the style that changes most as it ages: ink spreads slightly under the skin over the years, and lines drawn very close together can merge. Spots that see less sun and less movement, like the inner forearm or the back, keep it crisp the longest.
Previewing it honestly
In the editor, add a little Ink bleed to see the soft edges of healed ink, and raise Fade for the look in ten years. If two lines nearly touch in the preview, size the design up or choose a simpler one.