How to choose 3D scanning markers
A practical buyer's guide to reference markers for handheld 3D scanners and photogrammetry.
What reference markers do
Marker-based 3D scanners track their own position by recognising the pattern of reflective dots they can see. Each dot has a bright retro-reflective center inside a black ring; the scanner's cameras find the center precisely and use the dots that are visible in each frame to stitch the scan together. Without enough markers, flat, symmetric or featureless surfaces drift or fail to align.
Choosing the dot size
| 3 mm inner / 6 mm outer | Small parts, fine detail, close-range scanning |
| 6 mm inner / 10 mm outer | The standard size for most handheld laser and structured-light scanners |
| 12 mm inner / 19 mm outer | Large objects (vehicles, molds, castings), longer working distances, photogrammetry |
Your scanner manufacturer's manual lists the supported marker size — when in doubt, follow it.
Paper or plastic?
Our adhesive dots come in two materials. Plastic dots are the economical choice for flat parts. Paper dots reflect more strongly, conform better to curved surfaces and peel off easily after scanning, so they are worth it for curved or complex parts.
Adhesive or magnetic?
Adhesive dots stick to almost any surface and are single use. Magnetic dots hold only on steel and iron, leave no residue and can be reused — worth it if you scan steel parts regularly.
When to use spheres or towers instead of dots
If the part must not be touched, is too small to carry enough dots, or must be flipped and scanned from every side, put the markers around it instead. 13-face marker spheres show markers from almost any angle; marker towers and pyramids build a rigid 3D reference frame on the table or turntable. For large objects, use 12 mm target spheres.
Placing markers
- Use a random, non-repeating pattern — avoid straight lines and regular grids.
- Put dots on flat or gently curved areas, not on sharp edges or fine features you need to capture.
- Make sure several markers are visible to the scanner at all times; denser on small parts, sparser on large flat panels.
- Clean oily surfaces first so dots stay flat, and peel them off after scanning.
How many do I need?
A pack of 500 dots covers many small and medium parts. Labs and service bureaus that scan daily usually choose the 1,000-piece paper packs or the 10,000-piece plastic bulk packs.