Method to determine the satin-effect on metal plated substrates

1. Method to determine with a device constant k the satin-effect on metal plated substrates comprising the following steps:

i) irradiate a sample with light from a light source,

ii) detect the angular intensity distribution H(φ i ) of the backscattered light,

iii) determine both of the following parameters:

the Aq value of the angular intensity distribution H(φ i ), wherein the Aq value represents the variance of the backscattered light angle φ i multiplied with the device constant k

Aq=k *Σ(φ i −M ) 2 *H (φ i ) wherein M=Σφ i *H (φ i ) and

the integrated intensity of the angular intensity distribution, and

iv) compare both of the parameters to a target value.

2. Method according to claim 1 wherein the wavelength of the light ranges between 350 nm and 800 nm.

3. Method according to claim 1 wherein the wavelength of the light ranges between 610 nm and 760 nm.

4. Method according to claim 1 wherein the source of light is a LED.

5. Method according to claim 1 wherein the target value is determined from a sample having a predefined satin-effect represented by the Aq value, the integrated intensity or both.

6. Method according to claim 1 wherein the integrated intensity value is determined by integrating an interval of 10° to 15° and −10° to −15°.

7. Method according to claim 1 wherein the Aq target value ranges between 10 and 60.

8. Method according to claim 1 wherein the Aq target value ranges between 20 and 40.

9. Method according to claim 1 wherein the plated metal layer having a satin-effect is nickel.