Formation method of three-dimensional object with metal and/or ceramic particles and thin organic resin

A three-dimensional object formation method, comprising:

• forming a powder material layer comprising a powder material for three-dimensional object formation, the powder material comprising a particle which comprises:
• a base material, which is a metal particle, a ceramic particle, or both;
• and
• an organic resin provided on a surface of the base material;
• discharging a hardening liquid to the powder material layer, the hardening liquid comprising:
• a medium for dissolving the organic resin;
• and
• a cross-linking agent containing a site cross-linkable with a cross-linkable functional group of the organic resin;
• and
• repeating the forming of the powder material layer, and the discharging of the hardening liquid, to form a three-dimensional object;
• wherein a coating thickness of the organic resin on the base material is 5 nm or greater but 500 nm or less on an average thickness basis.