The clear drinking straws can be regarded as the main workhorses of the commercial integral magnetometers due to their "stealthy" properties. Interestingly, these properties are not related to their negligible weak magnetic properties. On the contrary, the magnetic susceptibility of the material of the straw is quite high for a diamagnetic substance: straw  8.8 × 10 -7 emu/g/Oe. At least, such a number has been established at room temperature for a 5 mm long piece of a straw coming from the same batch of straws used in this study. This is some 60-70% more than that of the capsules and of SRDM.