How to Do Image Masking in OBS (Step-by-Step)

If you’ve ever seen a streamer with a perfectly rounded webcam, clean overlays, or graphics that snap neatly into custom shapes, you’ve already seen image masking in action.

And here’s the gag: it’s not complicated.

You don’t need Photoshop. You don’t need plugins.You don’t need to be “good at tech.”

You just need one PNG file and a minute inside OBS.

This guide breaks down exactly how to do image masking in OBS, what it’s used for, and how to avoid the most common mistakes that make people think it’s broken.

I’m Novakane Omega, also known as Blak Gurl GamR. I’ve been streaming on Twitch for about five years now, and somewhere between going live night after night, DJing sets, and building loads of scene collections across both my channels, I realized something: OBS is way more powerful than most people think.

A lot of what people compliment as “clean overlays” or “custom graphics” on my stream aren’t expensive assets or fancy packages I bought. They’re layers. Masks. PNGs. A little chroma key here, a little intentional placement there. Just me learning how to make OBS work with my creativity instead of against it.

Because of what I’ve learned on Twitch, I now teach and coach other creators, sharing the same tools and shortcuts I use myself. Image masking is one of those techniques I rely on constantly, whether I’m gaming or DJing. It lets me create artful, colorful scenes that feel custom and intentional without spending money, hiring a designer, or overcomplicating the setup.

Every screenshot in this guide comes straight from my own stream. What you’re seeing isn’t theory. It’s what I actually use to build scenes that feel layered, dynamic, and polished using nothing more than Canva-made PNGs, a little creativity, and a solid understanding of OBS.

Now let me show you exactly how it works.

What Is Image Masking in OBS?

Image masking lets you control the shape and visibility of a source in OBS using a transparent PNG.

Instead of everything being a boring rectangle, masking allows you to:

• Turn your webcam into a circle or rounded frame

• Fit images neatly into custom overlays

• Layer graphics without awkward edges

• Create cleaner, more intentional layouts

Think of a mask like a stencil.

The visible part of the PNG reveals your source. The transparent or blocked areas hide everything else.

What You Need Before You Start

Before jumping into OBS, make sure you have the basics:

• OBS Studio (updated)

• A PNG mask file

  • Transparent background

  • Clear visible area where you want the image to show

• A source to apply the mask to:

  • Webcam

  • Image

  • Video

  • Media source

Optional but helpful:

• Canva, Photopea, or Photoshop to create your mask

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How to Do Image Masking in OBS (Step-by-Step)

This is the exact process. No extra fluff.

Step 1: Select Your Source

In OBS, right-click the source you want to mask.

Click Filters.

Step 2: Add an Image Mask/Blend Filter

Under Effect Filters, click the + icon.

Select Image Mask/Blend.

Step 3: Choose Your Mask Image

Click Browse and select your PNG mask file.

Make sure it has transparency where you want the source hidden.

Step 4: Set the Mask Type

Most of the time, use:

Alpha Mask (Color Channel) (What I used in these examples)

If your PNG uses built-in transparency and isn’t behaving correctly, try:

Alpha Mask (Alpha Channel)

This one setting is where most people get stuck, so don’t panic if you need to switch it.

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Step 5: Adjust the Source

Resize or reposition the source itself until it fits cleanly inside the mask.

Do not resize the mask image.

You can now overlay the source over another image or even a video and do all kinds of cool effects.

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Common Image Masking Mistakes (And How to Fix Them)

Nothing shows up at all: Your mask might be fully transparent or inverted. Check the PNG.

My webcam disappeared: Wrong mask type selected. Switch between Color Channel and Alpha Channel.

Edges look jagged or low quality: Your mask resolution is too small. Use a higher-resolution PNG.

The mask doesn’t line up Resize the source, not the mask.

What You Can Mask in OBS

Image masking works on more than just webcams.

You can mask:

• Webcam frames

• Alert boxes

• Static overlays

• Animated graphics

• Gameplay windows

• Lower thirds

• Social media pop-ups

If OBS sees it as a source, there’s a good chance it can be masked.

How to Create Your Own Mask (Quick Tips)

If you’re making your own mask:

• Use a transparent background

• White or visible areas reveal the source

• Transparent or black areas hide it

• Export as PNG

• Match your canvas size to your OBS resolution for cleaner edges

Canva is perfect for beginners.Photopea gives more control and is free.

Why Image Masking Instantly Levels Up Your Stream

Image masking is one of those small OBS skills that makes a huge difference.

It:

• Makes your stream look intentional

• Improves branding and layout flow

• Keeps visuals clean and professional

• Separates “just going live” from polished production

Once you learn this, you’ll start seeing your stream layout differently.

Final Tip

Start small.

Mask one source today. Round your webcam. Clean up one overlay.

That one change alone can make your stream look ten times more put together.