Report - Dark Flash


Name: Dark Flash
Source: Davis (et al)


percent parts component
50.00% 1 Potassium Chlorate
50.00% 1 Antimony Trisulfide

Required Mass


Diaper together the pre-milled and screened ingredients carefully.


A very sensitive and powerful composition, make and use with extreme caution.

The name may be an oxymoron, but its derivation is obvious; it produces little light but is a powerful report composition like most flashes. Sometimes called "dirty flash" or "dark report" composition.

Adding some Manganese Dioxide makes the composition significantly more sensitive and quite dangerous. Such a mixture is quite a good cap composition despite being quite a bit more friction sensitive than shock sensitive.

Ideal for breaking crossettes as it produces very little light, or anywhere else a minimum amount of space for a report composition is available, the power required is significant and a bright flash is undesirable.

This composition is also often used as a 1st-fire pyrogen for bridged e-matches. It's thermal sensitivity makes it a good choice, but its friction sensitivity needs to be managed, typically by coating over with something else, despite this such a match may still ignite from common abuse, like being stepped on.

The reaction is roughly:

3(KClO3) + Sb2S3 => 3(KCl) + 3(SO2) + Sb2O3

Which suggests a stoichiometric mixture:

52 KClO3 48 Sb2S3

Therefore conventional 1:1 is pretty close to stoichiometric.