Lap marks are those ugly stripes caused by uneven layers of paint buildup. They occur when you roll over paint that’s already partly dry. (In warm, dry conditions, latex paint can begin to stiffen in less than a minute!) The key to avoiding lap marks when doing DIY wall painting is to maintain a “wet edge,” so each stroke of your roller overlaps the previous stroke before the paint can begin to dry.
Interesting information! We just got scammed in White Stone, Virginia... we chose the same color, but went from a flat to an eggshell finish. I wasn't available to stand over the painter while he painted. For such a detailed job, I marveled at how quickly he finished the project! After he was paid for the job, we discovered all he did was roll paint across the walls and close to the crown, baseboards and detailed trim around windows and doors leaving about an inch or so of the flat finish. By using the same color, he didn't even do the job he was paid to do, which explained why he could finish the job so quickly. By using the same color... he got lucky and passed it off as a completed job not bothering to paint to and cut in around the trim. Upon further evaluation of our walls we could see exactly where he stopped because we could see the difference between the flat and eggshell finishes. There are walls he didn't even bother to paint. Then where he did paint near the crown when we were in the room watching ... he hit the crown moulding and tried to tell us it was already there... and tried to sell us on painting the crown moulding. I am so disgusted and upset!! He'll be hearing from us to rectify the situation.
Some contractors work on time and material others on a firm contract. I would never hire the former and am leary of the latter. A contractor may low-ball a bid to get the job planning to make a killing on change orders. If you say good morning to them, they charge you extra for that. If the contract is not very, very specific and extensively fleshed out or if they display their change order schedule prominently on top, show them the door.
When I had my interior painting done, after clearing out all of the furniture, myself, I also removed all of the wall plates in all the rooms to be painted. They were a beige color and probably yellowed. The wall was originally an off white and I had it painted a light-mid grey, so those wall plates would look terrible. After pricing replacement plates, switches and outlets (Would have been way too expensive to replace all of them), I decided to just paint all of the wall plates, switches and outlets (Used just a black gloss spray paint). I sprayed the plates outside and used a small brush on the switches and outlets. It worked out just fine and the blacks plates, etc compliment the wall color. It has been 7 years and the plates, switches, outlets are holding up well.