How to make a photo look vintage
Four adjustments in order: drop saturation a little, add a sepia or warm tone, reduce contrast slightly so the blacks lift, then add monochrome grain. The lifted blacks matter most — faded prints never have pure black, and that single detail does more than any filter.
The order matters
Colour first, texture last. Adding grain before you change the tone means the grain itself gets tinted and smoothed by the later steps, which flattens it. Finish the colour, then lay grain over the top.
A useful sequence: desaturate to about −30, apply sepia at 50–70, lower contrast by 10–20, then grain at 15–25.
Why lifted blacks sell the effect
Real prints fade from the shadows up. Ink and silver degrade, light scatters in the paper, and the darkest tone in an old photograph is a dark brown-grey rather than black. A digital image with pure black shadows and a sepia wash over it reads as a filter; lift the shadows and it reads as age.
Lowering contrast does this in one move. That is why the contrast step is not optional even though it sounds like the least interesting of the four.
Finishing touches
A vignette at 30–45 imitates the light falloff of old lenses and draws the eye inward at the same time.
A white border, or a full instant-print frame with a caption, completes the physical-object impression. An image that looks like a photograph of a print is more convincing than an image that merely looks faded.