Take the 2-minute tour ×
Travel Stack Exchange is a question and answer site for road warriors and seasoned travelers. It's 100% free, no registration required.

I recently travelled to the USA from Asia. When I arrived in Detroit they marked my E-cigarette with a clear colorless liquid using a small paint brush used for water colors.

What chemical(s) do they use as markers?

share|improve this question
As a related question what is the purpose of the marking? –  Phil May 27 at 23:59
@Phil: "marking" is to elicit a chemical reaction with compounds of explosives that most likely makes the clear liquid change color. –  Jonas May 28 at 8:52
@Jonas, thanks. I wasn't aware they did that with liquids too. Whenever I've been checked it's been with the cloth in in the wand thing –  Phil May 28 at 16:00
This question appears to be off-topic because it is about science/chemicals - not a travel question. –  Mark Mayo May 29 at 13:51
@MarkMayo But the fact that something similar may be experienced by travellers makes it relevant right? –  Vedant Chandra May 31 at 15:48

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.