Thicker rubber is used for stamps. This means that the engraving depth is greater. Thus, the power of the laser tube should be higher than that of the one used for producing seals. Another important point is that stamps are engraved in several runs. This should be noticed when choosing a l thicker rubber is used for stamps. This means that the engraving depth is greater. Thus, the power of the laser tube should be higher than that of the one used for producing seals. Another important point is that stamps are engraved in several runs. This should be noticed when choosing a laser engraving machine.