MDF skirting, architrave and flat panel doors usually arrive with a thin factory primer that is meant as protection in transit rather than a finished undercoat. Treating that primer as job done is the most common reason new joinery still shows machine marks once topcoated.
Usually yes on cut edges and lightly on the faces, since the factory coat is rarely enough on its own for a durable final finish.
That is almost always an unsealed cut edge absorbing paint differently. Sealing it before the next coat corrects the mismatch.
Brushing is possible but shows more brush marks on flat MDF than it would on grained timber. Spraying gives a noticeably smoother result.
It is thin, often sprayed fast, and rarely sanded before it left the factory. Machining marks, slight fuzz on cut edges and uneven sheen are all still present underneath it, and a topcoat sprayed straight over that will show every one of them under sidelight.
MDF edges cut on site are unsealed and absorb paint differently to the factory-coated faces, which is where flashing most often appears. Sealing every cut edge before priming stops that patchy look developing once the finish coats go on.
A brushed finish on flat MDF panels shows every stroke because there is no timber grain to disguise it. Spraying lays the material down evenly across large flat faces, which is why skirting runs and flush doors usually get sprayed rather than cut in by hand.
Tell us the joinery specification and we will confirm whether spraying on site or off-site suits the programme.
Factory primer on MDF is a starting point, not a finished coat, and cut edges need their own sealing step.
Speak to a Hampshire commercial decorating contractor that turns up, communicates clearly and delivers a finish that lasts.
