Wood trim painting is where the quality difference between a mediocre painter and an exceptional one is most visible. Cutting in cleanly against walls, getting full coverage on complex profiles, avoiding brush marks in the final coat, and maintaining consistency across every linear foot of trim in an apartment requires real skill and proper technique.
The Prep That Most Painters Skip
Before any trim paint goes on, every piece of trim should be: lightly sanded with 220-grit paper to degloss the existing paint surface and improve adhesion; wiped clean with a tack cloth or damp rag; primed with an appropriate primer (oil-based for new raw wood, shellac-based for knot bleeding, latex bonding primer for previously painted surfaces); and allowed to dry fully before finish coat application.
Primer Choice for Trim
Oil-based primer on trim used to be the professional standard — it penetrates wood, blocks stains, and creates an excellent substrate for alkyd or latex topcoats. In NYC apartments with limited ventilation, oil-based primers are increasingly problematic. High-quality shellac-based primers (Zinsser BIN) and advanced latex bonding primers are now viable alternatives that professional painters use in occupied residential spaces.
Paint Choice for Trim
Semi-gloss or gloss finish is appropriate for trim — it's more washable, more durable, and reads as intentionally different from the wall surface. Benjamin Moore Advance (waterborne alkyd) is the current professional standard for trim paint in NYC apartments: it levels beautifully (minimal brush marks), cures to a hard, durable finish, and is significantly lower VOC than traditional alkyd paint. Farrow & Ball full gloss is extraordinary on trim in apartments where the design level warrants the premium.
Technique for Clean Cut Lines
The difference between a cut line that looks professional and one that doesn't is in the brush quality and the technique. A high-quality 2-inch angled sash brush (Purdy Clearcut or Corona Excalibur) loaded correctly and pulled steadily along the trim edge produces a crisp, clean line without tape. Taping is slower, produces less consistent results on curved profiles, and leads to paint bleeding under the tape on textured walls. Skilled painters cut freehand.