The knife is the simplest, and there is a layer of red pigment on the blade, which is a bloody mouth when rubbed on the skin. The high-end is to make a fake skin with silica gel or pigskin and line it with a thin blood bag (fake blood, real blood is too expensive and unsanitary).

As for the kind that goes in, hold the soil with your arm, and the other is a magic blade with a spring inside.

===================

The shooting effect is relatively difficult. It is common that small plastic bags are filled with fake blood, and then there is a layer of gunpowder and ignition device behind them, which is padded under the clothes.

The grade of gunpowder directly determines the thickness of this layer. The thicker it is, the more fake it looks. I'm not sure about the composition of gunpowder. It has many uses. ...

At present, there are few pyrotechnics with formal qualifications in China. I only know five or six people, most of whom are undocumented.

So unless it has been touched, it is difficult to make it clear.