BTW, the reason I suggested the aluminium foil version is simply because most would already have that at home (it is standard kitchen foil, not heavy duty stuff) it is very cheap and yes it is light, less than 5g.
All you do is put some layer on top of the burner ( can be paper ,cloth...) and then shape a folded piece of foil over it. The idea of the layer in between is so that the "snuffer" can slide over the burner easier.
For some burners, like the White Box stove, the bottom of a soda can works very well.



Franco