Concept:
In printmaking, different tools are used for applying ink, spreading colour and transferring images.
A roller used for spreading ink evenly is technically called a brayer.
Step 1: Understand the function of a roller.
A roller is used to spread ink evenly on a surface such as a plate, block or printing area.
It helps in making the ink layer smooth and uniform.
Step 2: Identify the technical term.
The technical name for this roller is:
\[
\text{Brayer}
\]
It is commonly used in block printing, linocut, woodcut and other printmaking methods.
Step 3: Check other options.
Squeegee is used in screen printing to push ink through the screen.
Leather dabber is used for dabbing or applying ink in some intaglio processes.
Brush is a general painting tool.
So, the correct technical name for roller is Brayer.
Step 4: Final conclusion.
Hence:
\[
\boxed{\text{Brayer}}
\]