Samples generally can be divided into three categories
(a) non-transparent (opaque reflective) samples
(a) Non transparent (opaque reflective) samples
(b) Transparent Samples
(c) Translucent Samples
When comparing samples visually, e.g., standard to colour match, the samples should have at least one straight edge. This is essential as colours can only be accurately assessed by laying the standard and the reference side by side. It is also important to eliminate the mirror gloss effect for samples with a smooth gloss surface. This can be done by holding the samples at a 45° angle to the incident light. A small stand angled at 45° is useful for this purpose.
Samples should also have the same surface finish. It is impossible to assess accurately colour if one sample has a smooth gloss surface and the other has a textured surface.