Color consistency can be a challenge sometimes but here are some tips to keep everything looking right!
The problem most people run into is a variation in the color however there are times when there is a variation in the sheen of the coating that causes a problem. This happens but I will tell you how to avoid this.
1. One of the most important things to do when you are buying your paint is to buy it at the same location. Say for example you are buying your paint at Home Depot. There is probably several stores in your area and the formula is on the can but…the machines that tint the paint are calibrated and one machine can be calibrated slightly differently so you can end up with a can of paint with the same formula on the can but it is off. This tip holds true regardless of where you buy your paint.
2. This may sound obvious but “buy the same stuff”. Sometimes there may not be enough of a specific line of paint so people buy the same brand and sheen but it is a different grade of product. For example a flat latex Manor Hall is different then a flat latex Speedhide both from Pittsburg Paint.
3. Make certain the base is the same. Sometimes stores run out of a specific base and substitute a different base or it is an innocent mistake that they grab the wrong stuff.
4. Buy enough for the job plus a little extra. Quite often people go back a year later to buy some more paint for touch up and the store no longer carries that specific line anymore. They will most likely be able to match the color but this is when there is usually a problem with matching the sheen.
5. After you have purchased all the paint for the job; “box” all the paint together. What this means is to mix all the various gallons of paint together. If you have single gallons pour them into five gallon buckets and pour them back and forth to mix them together. If you have five gallon buckets you can get a couple extra fives and pour 1/2 of a five into the empty ones and pour them back and forth to mix them up. You can also use a drill and mixing paddle if you like.
If you follow these 5 guidelines you should be fine. Occasionally there are coatings that are sensitive to how they are applied. For example Sherwin Williams had a product called Everclean. It was actually a horrible product. It was suppose to be super washable, etc. but one of the things that became readily noticeable was when a wall was rolled the up roll looked different then the down roll. This was because of how the paint was laying down. The solution was to make sure all rolling ended with the same stroke, usually down.
There are some paints, much better then Everclean, that are sensitive to the roll so a good technique is to always finish with a roll down.