The size of a business card so that it fits into the standard wallet.

Grayscale ① for white balance post-processing correction.

Colour chart ② to standardize colour descriptions of visible pigment. Used like a Munsell colour system, we can now describe colours to each other that we will all be able to reference and verify.


Iron-crosses ③ for photogrammetry. Most Structure-from-Motion (SfM) photogrammetry software allows for the automatic detection of these crosses. By providing a known distance, it can simplify scaling of rock art panels.

Frequently Asked Questions

1. Why 7 cm?

In order to keep the card small enough to fit in a wallet, sacrifices had to be made. We had to scale it down to 7 cm.

2. What if the colour is not in the colour chart?

Like a Munsell, fractions can be used to describe in between colours. Please let us know if there is any colour you feel needs to be included in the chart.

3. Is 4 cm distance for a photogrammetry scale too short?

Depends on the subject. It should be sufficient for figures and panels that are a few square-meters in size. We encourage using several scales at different orientations for a more accurate model. If recording the entirety of a larger site by photogrammetry, sticking two of these cards to a ruler will be more effective.

4. How did you pick the colours in the colour scale?

These were identified by the PERAHU team as the most common colours found in Australian rock art.

5. Why are different shades of blue included?

At some sites in Australia, reckitts blue (washing dye) was used to make a paint after being obtained from European settlers. So it is a useful colour for Australian rock art.

6. Will there be updates?

Yes, the current card is version 1, the prototype. We will gather feedback and possibly incorporate changes into the next version. Please let us know if you have any suggestions.

7. Where can I get one?

Email us at

Check back! We will be uploading the colour names and hex numbers for your reference

Rock art scale

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