When painting the trim, you don’t have to be neat. Just concentrate on getting a smooth finish on the wood. Don’t worry if the trim paint gets onto the walls. You’ll cover it later when painting the walls. Once the trim is completely painted and dry (at least 24 hours), tape it off (using an “easy release” painter’s tape), then paint the ceiling, then the walls.
Back to the article. You can add water to all latex based paints / thinner to oil based paint. The tinting base has absolutely nothing to do with it. Say you are working outside and throughout the day you have to add a little water to keep the same consistency. If somebody really tried to add 20% to 50% water they no longer would be painting they'd be performing a whitewash or pickle finish.
I do not mean to come off with an edge, however, this is an article for people hiring low bid, uninsured, one man band painters out to "hustle" a buck. Hire reputable, established companies or hire someone you know or have a strong referral from. If you are arguing over watered down paint, ticky, tacky deposits, buying your own supplies, you have hired the wrong guy.
I hired this person because he was listed on Angie's List. This man claimed he took and passed his contractor's license test after he signed me up for a project (Feb.) that included fixing cracks, painting, repairing a gate, installing a screen door, etc. He said he would charge me the original "handyman" prices. He postponed the start date, brought one worker who fixed a few cracks, repainted the gate terribly, but ruined a dining room ceiling when his worker used silicone in a tube instead of the expansion tape, spray ceiling covering, and paint I had purchased saying this silicone was "better". Then they said they would have to paint the whole ceiling and charge extra. They left holes in the walls and did a sloppy paint job in several places. I just paid them to get them out of my home as I felt intimidated as a senior citizen who is handicapped. I will try to have the main guy come back when I let him know what I need redone. Don't know if he will come back without charging me more.
House Painter Contractor