Three-dimensional printing

A method for three-dimensional (3D) printing, comprising:

• applying a metallic build material;
• patterning at least a portion of the metallic build material based on a 3D object model, the patterning involving:
• selectively applying a wetting amount of a binder fluid on said at least the portion of the metallic build material;
• and
• subsequently selectively applying a remaining amount of the binder fluid on said at least the portion of the metallic build material;
• wherein an area density in grams per square meter (gsm) of the wetting amount ranges from about 2 times less to about 30 times less than an area density in gsm of the remaining amount;
• repeating the applying of the metallic build material and the patterning to create a patterned intermediate part;
• and
• activating a binder of the binder fluid to form a cured intermediate part.

A 3D printing composition, comprising:

• a patterned build material layer, comprising:
• build material particles;
• interstitial spaces between at least some of the build material particles;
• and
• a binder fluid at least partially filling the interstitial spaces and having been applied in a wetting amount and a subsequent remaining amount;
• wherein a surface roughness of the patterned build material layer is reduced by at least 40% compared to a surface roughness of a second patterned build material layer having the binder fluid applied thereon in a single amount.