Cutting in is one of the most critical stages in painting. It involves making precise, straight lines along all the edges where one paint color or flat surface meets another, including doorways, wall trim, and window sashes. 

But finding the best paint brush for cutting in is a matter of taste and what you learned on. It's essential to understand the type of bristles, length of handle, and brush shape that will give you crisp lines. Getting a professional finish while cutting in without painter's tape can save you time and money, especially if you're a pro. But we have found that every painter is different, and no one brush is best for all cut-in applications or users. So we encourage you to try a bunch out and make an informed decision. 

The tips and options below can give you insights and an understanding of when and where to use different brushes for cutting in.

While some painting tools claim to simplify painting projects, it's best to stick with a simple brush that's not too wide or long. The best brushes for cutting in for most jobs are trim brushes. However, you may also need sash brushes to finish some areas.

• Trim brushes: Intended for painting narrow pieces of wall, door, and window trim, as the name suggests. They're available in a wide range of sizes and straight or angled edges. 
• Round Sash brushes: Unique because they feature a rounded profile, allowing them to get into recessed areas with less mess.

The type of paint you're using — oil-based or water-based — affects which type of brush is best:

• Natural bristle brushes: Best for holding oil-based paint but usually cost more than synthetic bristles. Avoid using natural bristle paint brushes with water-based paint. The water can penetrate the bristles and soften them, affecting the crispness of your cutting-in lines.
• Synthetic bristle brushes: Slightly cheaper and best for water-based paint. Getting oil paint out of synthetic bristles is hard because it bonds with the material, so choose a synthetic brush if you're using water-based paint.
• Hybrid or blended paint brushes: Have a mix of natural and synthetic bristles on the same brush. They work well with both oil- and water-based paints, as long as you clean them properly between switching. Hybrid brushes last longer than fully synthetic-bristle brushes and cost less than fully natural-bristle brushes.

For cutting in, stiff bristles are better for crisp lines, but a brush that is too stiff will leave marks. Select a medium to high stiffness to maintain a steady line while achieving a smooth finish. As the bristles break in and become softer from use, consider getting a stiff new paint brush for cutting in.

You'll have to choose between angled, round, and flat brushes before starting your paint project. Depending on your skill and plans, you may need all three.

Angled paint brushes are one of the best types for cutting in — they work well for covering trim and making clean joins in open corners. 

Straight brushes are best for long, straight areas with no corners or intrusions. 

For example, you may want to use an angled brush for the corners of a room, then switch to a straight trim brush for ceiling trim and floorboards in the center of each wall for straighter lines.

The rounded shape of the sash brush's bristles makes it ideal for dabbing paint in tight corners, under raised molding profiles, and around window sashes. You may not need it if you don't have many of these features to cut in.

The best angled paint brush for cutting in is a two- to three-inch brush.

You don't want to go too narrow when choosing the best brush size for cutting in. Narrow trim brushes give you more control over the paint line, but you are forced to go back to the cut-in bucket to recharge your brush too often due to the low amount of paint a smaller brush holds.

• Two-inch brush: Often too narrow to provide straight lines on long runs, but works well for touching up around window edges and doorknobs.
• Three-inch brush: Ideal for long runs of cutting in.

The last detail to consider when choosing a paint brush for cutting in is the handle:

• Ergonomic handles: Reduce hand fatigue during long projects. Shaky hands lead to uneven lines and other mistakes.
• Wood handles: Provide the best grip for detailed work, whereas plastic handles get slippery if you sweat or paint runs up them.

For working with stiff bristles to cut in, aim for a handle length of around six to eight inches.

Regardless of the best cutting-in paint brushes you choose, clean cutting in is largely a matter of technique. Almost any decent small hand brush can produce clean paint edges with the right amount of paint, a steady hand, and a straight stroke pattern. These tips will help you adjust your technique to get the best results, no matter which brush you use:

• Point a bright light source, such as a clamping work light, at the surface you're working on and avoid blocking the light with your body.
• When wiping excess paint off the brush, don't scrape the bristles along the paint bucket's edge. Just pat it against the side to leave paint on the brush.
• Hold the brush at a 30° angle and apply the paint smoothly.
• For challenging areas where you can't get a crisp edge, apply painter's tape or hold a painter's shield.
• Cut in for a total of two to three inches of space from the ceiling, trim, or baseboard to give yourself enough room when rolling up to your cut-in line so you don't hit the surface.
• Start your cut in by placing your loaded brush about two to three inches below the corner you are cutting up to and bringing the brush up to the corner. This keeps you from dumping a bunch of paint next to the ceiling or trim where it's harder to control

There are so many personal preferences you may have when cutting in. For example, a rat-tail handle might give you a better grip for smoother lines, or a wider beaver-tail style handle might be more comfortable. 

Experiment with different angled tips to build your skill with both narrow and wide cut-in lines. Don't be afraid to tape off some straight lines in the middle of a wall that's still waiting for paint and practice cutting in along the tape to build your skill.

Hyde Tools has everything you need for those challenging paint projects, from paint brushes to paint applicators. Explore our selection to find the right cutting-in brush to get smooth results, and contact us with any questions.