After a couple of decades, old prints will begin to deteriorate. Humidity and moisture brings fungus growth, handling leads to scratches and folds, dust and grime accumulates on the surface and excessive sunlight causes cracks.
We can recreate the effects of time by combining texture with our digital images. Photoshop textures such as the one above are very easy to go out and shoot yourself.
Copy in a suitable texture image then experiment with different Blend Modes to combine it with the layers below.
Each Blend Mode will behave differently and in ways that are often difficult to predict, so it’s a good idea to scroll through different modes, either with your mouse wheel or with the keyboard shortcuts Shift + or Shift – until you get the look you want.
Overlay, Soft Light, Color Burn and Multiply can work well. Don’t forget you can fine-tune the texture with the Layer Opacity slider if you want to make the effect less intense, and add a Layer Mask then paint with black to make it work more selectively over the image.