1. Mesh soil should be "wood knot soil", that is, black clay, which is non-corrosive and sticky.
2. Make a model, which should be called "prototype"
3. Soap water should be "potassium soap water". Use concentrated potassium soapy water solution.
4. Pour the stirred gypsum slurry on the prototype. Larger models can be fitted on the outer ring.
5. When the plaster is dry and hard, dig out the soil inside. If the prototype structure is complex, it is necessary to make a separation line at the high point of the prototype, and then divide the peripheral gypsum block into several pieces for demoulding.
6. Spread the "potassium soap" solution evenly on the inside of the gypsum mold, not too thick, otherwise it will affect the shape.
7. The gypsum slurry is injected into the gypsum mold again. When operating, tap the gypsum mold lightly to make bubbles in gypsum slurry float out.
8. demoulding can separate the mold (it can be used many times). Be careful when you break the shell, so as not to hurt the finished product.
Fine figure statues are generally made of silica gel, which is a professional job that requires great skills.
Crafts can be copied with the original model, and need not be reshaped.
When you create your own, you can also use soil as a material to shape it (pay attention to keep the humidity of the soil and cover it with plastic sheets)
Large containers can be filled with bricks, wood blocks, newspapers and other sundries, and then soil or sludge can be added.
Clay or black clay is the most economical material.
Do it first, then ask questions. Making plaster model is a university question.
Have fun practicing!