Add dust and scratches to a photo in Photopea (free)

Open the photo, place a dust plate, set it to Screen. Three steps, no Photoshop needed.

Photopea is a free browser editor that reads layers and blend modes just like Photoshop. It is all you need to age a photo convincingly.

Step by step

1. Go to photopea.com and open your photo with File → Open.
2. Download a plate from the dust & scratches collection. Light dust is a safe start.
3. In Photopea choose File → Open & Place and pick the dust JPG. Press Enter to confirm placement.
4. In the Layers panel, change the mode from Normal to Screen. The black disappears.
5. Lower the opacity if the marks feel too strong, then File → Export as → JPG.

Make it believable

• Combine two plates. A light dust plate plus a few scratches looks more real than one heavy plate.
• Rotate for a series. If you post several images, rotate or flip the plate each time so the same speck is not in the same place.
• Add grain first. Real dust sits on top of grain. Add a grain plate in Overlay, then dust in Screen above it.
• Dark dust for negatives. On a scanned negative look, dust is dark. Invert the plate (Image → Adjustments → Invert) and use Multiply.