Confirm the exact surface
“Polyurethane floor” can describe different build-ups and finishes. Some systems are seamless, others include cushioned layers or factory finishes. Identify the product and age before specifying a line paint.
Match movement and hardness
A brittle coating over a flexible surface can crack or release. Product compatibility is more important than generic labels such as hard-surface paint. Use written manufacturer information or a specialist specification when the floor system is known.
Control the edge
Clean edges depend on suitable masking, pressure, application rate and removal timing. Test the tape on an inconspicuous area first. Tape that bonds too aggressively can mark a finish; tape that releases too easily allows bleed.
Inspect after cure
Check the line from several angles, then inspect adhesion and edge quality after the full cure period. Do not judge only while the paint is wet. Record any tackiness, gloss difference or surface reaction before the hall returns to use.