Mixing Interior and Exterior Paint: A Comprehensive Guide on Do's and Don'ts

Mixing Interior and Exterior Paint: A Comprehensive Guide on Do’s and Don’ts

Ever wondered if you can mix interior and exterior paint? You’re not alone. This is a common question for DIY enthusiasts and professional painters alike. Whether you’re looking to save money or create a unique color, mixing paints can seem like a tempting solution.

However, it’s not as simple as it sounds. There are key differences between interior and exterior paints that can impact the final result. So, before you start pouring paints together, it’s important to understand what you’re dealing with.

In this article, we’ll explore the ins and outs of mixing interior and exterior paint. We’ll delve into the potential benefits, drawbacks, and considerations to keep in mind. So, let’s get started and find out if this creative solution is a viable option for your next painting project.

Key Takeaways

  • Mixing interior and exterior paint may seem like a tempting solution for DIY enthusiasts and professional painters looking to save money or create unique colors, but there are key differences between the two that can impact the final result.
  • Key features of interior paint include resistance to scuffs, marks, physical damage, and low levels of Volatile Organic Compounds (VOCs). Additionally, it offers a range of finishes – flat, satin, eggshell, and high-gloss.
  • Exterior paint is designed to withstand harsh weather conditions, has high VOC levels, and generally offers limited finish options – most commonly flat, satin, or gloss.
  • Crucial differences between interior and exterior paint to consider when mixing include the formulation, VOC levels, finish variety, and resistance. Notably, interior paints have lower VOC levels and more finish options but are less resilient to outdoor elements than exterior paints.
  • While there are some advantages to mixing interior and exterior paints, such as versatility and budget optimization, potential drawbacks include reduced performance, inconsistent and unstable mixture, health risks due to increased indoor VOC levels, and uncertain longevity.
  • Before deciding to mix interior and exterior paint, understand your paint’s composition, the nature and location of the surface you’re painting, the desired longevity of your paint job, and the VOC levels in the paint.

Combining interior and exterior paint can be tempting for certain projects, but it’s important to understand the implications. Sherwin-Williams explains the differences in formulas and why they matter for the durability and finish of your paint job. For those looking to repurpose leftover paint, Benjamin Moore discusses creative ways to use up excess without compromising on quality or aesthetics.

Understanding Interior Paint

Understanding Interior Paint

When it comes to interior paint, it’s necessary to comprehend its unique characteristics. First and foremost, it’s crafted specifically for indoor conditions. Unlike exterior paint, it’s formulated to be more resistant to scuffs, marks, and physical damage.

When you handle a paintbrush or roller, you might have noticed the smooth and thick consistency of interior paint. That’s due to its renowned feature of high opacity. What does this mean for you? Simply put, it assures you flawless, even coverage with less coats. Yes, that means a considerable amount of time, energy, and paint saved in your painting project!

Another noteworthy attribute of interior paint is its low VOC (Volatile Organic Compounds) level. VOCs are those notorious chemicals that can pose health risks and emit a strong odor. With interior paint’s low VOC level, your painting job becomes more pleasant and less hazardous. However, it’s crucial not to underestimate the essentiality of wearing a mask and ensuring proper ventilation while painting.

Next, let’s take a moment to appreciate the rich diversity of finishes available in interior paints. From flat, satin, eggshell, to high-gloss, the choice is all yours depending on your aesthetic preference and practical needs.

Let’s have a glance at some basic differences between interior and exterior paint:

AspectInterior PaintExterior Paint
VOC LevelLowHigh
ResistanceScuffs, marksWeather conditions
FinishWide rangeLimited options

Remember, knowing your paint well is half the battle won. As we’ve delved into the aspects of interior paint, you’re now one step closer to making an informed decision regarding mixing paints. Later in the article, we’ll next turn our attention to understanding the intricacies of exterior paint.

Understanding Exterior Paint

Understanding Exterior Paint

Transitioning from indoor paints, exterior paints have unique properties catered to withstand the harsh outdoor environments. Let’s dive deeper.

Exterior paint is primarily designed to resist different weather conditions – from heavy rain to intense heat. This attribute is attributed to its high resistance properties including UV resistance and water resistance. High-quality exterior paints will also resist color fading and can last up to 15 years!

Markedly different from interior paints, exterior paints clock in much higher VOC levels. VOCs (Volatile Organic Compounds) are carbon-based compounds that readily evaporate at room temperatures. These VOCs help exterior paints dry faster and spread uniformly over surfaces. But, be aware! While it makes the job easier, higher VOC contents may pose health and environmental risks. Key fact: Always wear protective gear while handling high-VOC paints!

Then there’s finish variety in exterior paints. Unlike interior paints, you’ll find the options are somewhat limited – most falling under either flat, satin, or gloss finishes.

The table below presents the key differences between exterior and interior paints:

Interior PaintExterior Paint
FormulationSpecially Formulated for IndoorsResistant to Outdoor Conditions
VOC LevelsLowHigh
Finish VarietyDiverseLimited (Flat, Satin, or Gloss)
ResistanceLimitedHigh (UV and Water Resistant)

Exterior paint is not just about protecting and beautifying your home’s outer shell, it’s about standing up to the elements. Be it sun exposure, moisture, temperature changes or dirt – a good exterior paint fights them all. Knowing these features help you make the right choices about mixing paints. How about blending them? The next section will tell you all you need to know.

Key Differences Between Interior and Exterior Paint

Now that we’ve unpacked the specifics of exterior and interior paint, it’s time to highlight the key differences between them. Recognizing these distinctions is crucial when you’re considering mixing the two.

Formulation plays a significant role in how each type of paint performs. Interior paints are designed to offer smoothness and easy cleaning, with fewer VOCs for better indoor air quality. Diving deeper, you’ll find that they often contain more pigment for a richer color and less resin, ensuring a smooth application. On the other hand, exterior paints are compounded to resist harsh weather conditions. They contain more resin to adhere to surfaces exposed to outdoor elements and include additives to prevent mildew and fading.

Let’s delve into VOC levels. As noted, interior paints have lower levels of VOCs compared to exterior paints. But why is this important? VOCs, or Volatile Organic Compounds, are solvents that get released into the air as the paint dries. Breathing in high volumes of VOCs can lead to health issues.

Here’s a simple comparison table of VOC levels in typical paint products:

Paint TypeTypical VOC Level
InteriorLow – Medium

Moving on to Finish Variety, interior paints provide you with several options – from flat to eggshell, satin, semi-gloss, and high gloss. These choices can fine-tune the appearance and durability of your indoor spaces. However, exterior paints don’t offer this luxury. They’re typically available in either flat, satin, or gloss finishes.

Lastly, keep in mind the Resistance Factor. Exterior paints are champions when it comes to withstanding UV light, water, and varying temperatures. They’re formulated to last up to 15 years without noticeable degradation in color or quality. On the contrary, interior paints are less resistant to these external factors.

That’s a snapshot of the key differences between interior and exterior paint that matters when thinking ‘Can you mix interior and exterior paint?’ Understanding these differences can save you from potential painting pitfalls and keep your spaces looking their finest.

Pros and Cons of Mixing Interior and Exterior Paint

Pros and Cons of Mixing Interior and Exterior Paint

When faced with the question of whether it’s possible to mix interior and exterior paints, you’ll find varying opinions. Let’s delve into some pros and cons to consider when contemplating this mix.


A key advantage of mixing interior and exterior paints is versatility. Leveraging the durability and resilience of exterior paint with the smoothness and easy-clean features of interior paint can create a customized option for unique surfaces. You might discover it’s adaptable to a wider range of surfaces compared to using either in isolation.

Another perk can be budget optimization. If you’ve leftover paint from a recent project, combining the two can prevent waste, saving money without the need to purchase new paint.


Despite some advantages, the drawbacks of mixing interior and exterior paints generally outweigh the thought of positive aspects. One key con is reduced performance. While combining the properties of both types may seem appealing, this can dilute the effectiveness of each paint – leading to unsatisfactory results.

Particularly, exterior paint components designed for resistance against harsh climates can react poorly with interior paint ingredients, leading to an inconsistent and unstable mixture.

The mix could also pose a health risk. Interior paints are formulated to minimize VOC levels, limiting potential health risks when used indoors. However, blending interior paint with VOC-heavy exterior paint can increase indoor VOC levels, impacting indoor air quality.

It’s also worth noting that the longevity of the mixed paint is uncertain. Exterior paint by itself can endure extreme conditions for up to 15 years. However, the added ingredients from the interior paint can alter the outdoor endurance capacity, potentially leading to a lack of longevity.

It’s essential to consider these pros and cons when deciding whether to mix interior and exterior paints. Your decision will ultimately depend upon your unique situation, including surface type, budget constraints, and long-term expectations.

Considerations Before Mixing Interior and Exterior Paint

knowing the potential risks and benefits of mixing interior and exterior paint, it’s time to delve deeper into this topic. Prior to jumping into the painter’s mix, there are a few key considerations to keep in mind. Here is what you need to have under your belt:

Understand Your Paint’s Composition

First off, knowing the components of your paint is essential. Exterior paint consists of high levels of resin to withstand harsh weather conditions. Conversely, interior paint predominantly contains pigments that offer rich, vibrant colors and lower VOC levels to maintain better indoor air quality.

Recognize the Surface

Your surface’s nature and location make a difference. Is it exposed to harsh weather conditions? If yes, an exterior paint should be the basis of your mix. Is it situated indoors and wants a long-lasting, vibrant color? If yes, leaning more on interior paint will be beneficial.

Assess the Longevity

The longevity of the mixed paint is uncertain. It varies on a case-to-case basis. It might work wonders for someone while for others it might not. So, you need to get ready for some trial and error.

Check VOC Levels

Lastly, and perhaps most importantly, check the VOC levels. Paints with high VOC levels can have serious health impacts. Can you compromise your health for a perfect shade of color? Think twice.


So you’ve learned that mixing interior and exterior paints isn’t a straightforward task. It’s crucial to consider the composition of each paint type and the conditions your painted surface will face. Remember, exterior paint’s high resin content offers durability, while interior paint gives you those vibrant colors and healthier indoor air with lower VOC levels. While it might be tempting to mix and match, be aware of the potential longevity issues and the risks of higher VOC levels. It’s a balancing act between color quality, durability, and health risks. Proceed with caution, and don’t be afraid to experiment on a small scale before committing to a larger project. Your perfect paint blend could be just a mix away.

Can You Mix Interior and Exterior Paints?

Yes, it is possible to mix interior and exterior paints. However, the different compositions of each type of paint may lead to unpredictable results. It’s advisable to understand their specific properties, like exterior paint’s high resin levels for durability, and interior paint’s vibrant colors and lower VOC levels for indoor air quality.

What Factors Should I Consider When Mixing Interior and Exterior Paints?

You should consider factors like the surface’s exposure to weather conditions and the expected longevity of the mixed paint. Checking VOC levels is also important to manage potential health risks associated with high VOC levels.

Is There a Need of Trial and Error Approach While Mixing Paints?

Yes, due to the unpredictability of mixing interior and exterior paints, a trial-and-error approach might be necessary. It’s suggested to perform small-scale tests before committing to large scale paint jobs.

What are the Possible Health Risks from Mixing Interior and Exterior Paints?

Mixing the two types of paint may result in higher VOC levels, which have health risks. Prolonged exposure can lead to symptoms like headaches, vomiting, and in severe cases, damage to the liver, kidney, and central nervous system.

How Do I Balance Color Quality and Health Concerns?

Reference the VOC content in the interior and exterior paints you are considering. Opt for paint mixtures that prioritize vibrant colors while also maintaining low VOC levels to protect indoor air quality. Your health should be the primary concern.