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 used to work at Sherwin Williams. The best thing to do is specify that you will purchase your own paint. If the painter objects strenuously, he was plaanning on making money in the ways this article outlines. You might pay a few dollars more for paint, but you will have control of the quality of what goes on your walls. Never skimp on paint quality.
In England, little is known of the trade and its structures before the late 13th century, at which paint guilds began to form, amongst them the Painters Company and the Stainers Company. These two guilds eventually merged with the consent of the Lord Mayor of the City of London in 1502, forming the Worshipful Company of Painter-Stainers. The guild standardised the craft and acted as a protector of the trade secrets. In 1599, the guild asked Parliament for protection, which was eventually granted in a bill of 1606, which granted the trade protection from outside competition such as plasterers.
When the homeowner is at the point of hiring a painter, they generally will have colors selected or at the very least a color in mind. I always ask for the colors before I bid a job. Dark colors, high sheen colors and specialty finishes require more labor, this drives price. If its not a color change or I'm going over a similar color I give the pricing option of one or two coats. The best advise I can give based on 25 years in the business is to put it all in writing,colors, brands of paint preferred, when the work can be done, who moves furniture and how payment will be handled. I never get up front money. BTW you most definitely get what you pay for with paint. Higher quality products results in and better looking job. Don't be a cheapskate when it comes to paint or the painting contractor. House Painting Home Painters Highlands Ranch Colorado Click Here