This is my solution for creating filament sampling.
The size of the palette is 30x30x2mm, in the upper part I have foreseen the insertion of three lines of text indicating:

• Type of material
• Color
• Brands

In the lower part I have provided a window divided into three sections with different thicknesses (0.10mm - 0.20mm - 0.30mm) which will allow you to evaluate the transparency of the material in relation to the thickness.

In the 3mf file you will find different palettes with different descriptions that can be modified according to your needs (see attached images), obviously the printing materials must also be set based on the sample.

Print what you need and only after having set the parameters described above.

If you need an organizer to store your samples you can find it at the link below:

https://makerworld.com/en/models/111757