Three-dimensional printing

A method of modifying surface hydrophilicity of a three-dimensional (3D) printed object, comprising:

• based on a 3D object model, selectively applying a core fusing agent on a first layer of polymeric build material to form a patterned portion;
• exposing the first layer to energy to selectively coalesce the patterned portion and form a core layer;
• applying a second layer of the polymeric build material on the core layer;
• based on the 3D object model, selectively applying a primer fusing agent on at least a portion of the second layer to form a second patterned portion, the primer fusing agent including a plasmonic resonance absorber having absorption at wavelengths ranging from 800 nm to 4000 nm and having transparency at wavelengths ranging from 400 nm to 780 nm;
• based on the 3D object model, selectively applying a hydrophilic agent on at least a portion of the second patterned portion, wherein the hydrophilic agent includes from 1 wt % to 12 wt % of a hydrophilic polymer dissolved in an aqueous liquid vehicle, wherein the hydrophilic polymer has a molar mass ranging from 1000 g/mol to 12,000 g/mol and is water-absorbent at a water to hydrophilic polymer weight ratio from 2:1 to 1000:1;
• and
• exposing the second layer to energy to selectively coalesce the second patterned portion and form a 3D object layer having a hydrophilic portion.