The Ultimate Guide to Mixing Leftover Paints the Right Way, According to Pros

published Aug 27, 2020
We independently select these products—if you buy from one of our links, we may earn a commission. All prices were accurate at the time of publishing.
Couple painting house wall

If you’ve found yourself with a seemingly endless supply of mostly-empty cans of paint, it may feel like tossing those cans in the trash is your only option. But one of the most efficient and fun ways to consolidate your supply is to mix your own paints. And yes, keeping some leftover paint is important for potential touch-ups down the line, but that doesn’t mean you need to hang onto everything! Here, paint experts offer tips on how to best mix different paints to create a custom color, and highlight some of the potential pitfalls you’ll want to avoid.

Pre-mix the colors you’re going to work with

Step number one before combining paints is making sure that the paints you already have are mixed and ready to be used. When you purchase paint, it’s usually mixed in-store with a powerful mixer to combine all the ingredients—but if yours have been hanging out on your storage shelf for a while, you’ll want to stir it up with a wooden paint stick to blend the pigments and paint skin that may have formed or separated over time.

Try to mix similar paint types

One of the challenges of having lots of different partially-used cans around is that they may vary in the type of paint, sheen, chemical components, application, and more. “It’s important to look at intermixing like qualities and chemistries,” says Rick Watson, director of product information and technical services at Sherwin-Williams. “For example, issues may arise when mixing water-based interior acrylic latex with water-based interior vinyl latex because they may not blend well together, much like how oil and water do not blend together.” Instead, try to pair like with like, and try to use paints of similar ages for maximum compatibility. Otherwise, you risk issues with adherence.

Be conservative when it comes to where to paint

Since you’re effectively working on a low-stakes science experiment, you’ll want to use your custom-mixed paints in specific locations and spaces based on the types of paint you’re working with. If you’re mixing interior paints, make sure you only use them on interiors, and you may even want to consider if there are any guarantees or warranties that come with your original paints. You’ll want to be cautious in applying your creations in some areas: “I would not mix paints on the exterior of your home, where durability and quality finish are critical,” cautions Rick Watson, and he also recommends doing a patch test or two before going all-in and painting a whole wall or room.

Estimate your coverage wisely

Starting a painting project and running out of a unique shade of paint is one of the most frustrating situations for a DIYer, since it can be a real challenge to accurately mix paints and get the same result, Rick Watson points out. So make sure you’re paying attention to the quantity of paint you’re creating, the number of coats you’ll need, and even the surface that you’re painting and how absorbent it is.

Do larger batches once you have a finalized color mix

Once you’ve managed to successfully combine colors and paint types to your liking, consider doing a larger-scale mix of the same batch. If you’re working on a big project, Rick Watson recommends doing multiple gallons of the same product before using them, so that you have batch-to-batch consistency in color, sheen, and texture for multiple coats and later touch-ups. This is the best way to avoid slight color differences if you’re painting several walls or rooms the same color, but realize that you didn’t mix enough from the beginning. If you’re working on a smaller scale—a piece of furniture, a single wall, or maybe a door—you won’t need gallons, but you will need to make sure you have enough to adequately cover the piece in two to three coats, plus some extra for touch-ups.

Invest in the right tools

If you’re going to be mixing larger batches, make sure that you have the right sized containers and mixers for the quantities you’ll be creating. The ability to close the container with an airtight seal is important if you plan on reusing the paint later or need to apply multiple coats, so make sure you use a vessel with a lid.

Then: have fun! The great thing about this kind of project is that it’s often relatively easy to fix a paint job you hate, so don’t be afraid to take chances. Stick with low-stakes projects—i.e., not your brick fireplace or the exterior of your home—and experiment with creating your own dream color. Happy painting!