Three-dimensional printing

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

• identifying an electrical conductivity value for a resistor that is to be 3D printed, the electrical conductivity value being within a range of from 1.E+03 S/m to 1.E+05 S/m;
• based upon the identified electrical conductivity value, selectively applying a predetermined amount of a conductive agent to at least a portion of a build material layer in order to introduce a predetermined volume percentage of a conductive material in the conductive agent to the resistor, wherein the predetermined volume percent of the conductive material ranges from greater than 2 vol % to about 10 vol %, based on a total volume of the resistor;
• based upon the identified electrical conductivity value and the predetermined volume percent of the conductive material, selectively applying a predetermined amount of a resistive agent to the at least the portion of the build material layer in order to introduce a predetermined volume percentage of a resistive material in the resistive agent to the resistor, wherein the predetermined volume percent of the resistive material ranges from 0.05 vol % to about 10 vol %, based on the total volume of the resistor;
• and
• exposing the build material layer to electromagnetic radiation, whereby the at least the portion coalesces to form a layer of the resistor.