The luminance contrast test is always in terms of two samples in a pair, typically one bright color sample and one dark color sample. There are two scenarios for sample preparation:
- Side-by-side flat surfaces
- TGSI studs on a flat surface
Side-by-side flat surfaces
For side-by-side flat surfaces, two flat-panel samples need to be submitted. Shown below is an example:

The preferred sample size is 100 mm x 100 mm or slightly smaller. The maximum sample size is 300 mm x 300 mm. Only 1 pair of samples (2 pieces) are needed and it is optional to provide additional samples as the backup.
TGSI studs on a flat surface
For Tactile Ground Surface Indicator (TGSI) studs on a flat surface, it is possible to submit the samples as either integrated samples or loose samples.
Integrated samples
Shown below is an example of an integrated sample of TGSI studs on a flat surface:

The preferred sample size of the integrated sample is 100 mm x 100 mm or slightly smaller. The maximum size is 300 mm x 300 mm. Only 1 sample is needed and it is optional to provide additional samples as the backup.
Loose samples
It is possible to submit TGSI studs and flat surface samples separately, without fixing them. Shown below is an example.

It is recommended to provide 2 – 5 loose TSGI stud samples.
For the flat surface sample, the preferred sample size is 100 mm x 100 mm or slightly smaller. The maximum size is 300 mm x 300 mm. Only 1 sample is needed and it is optional to provide additional samples as the backup.