A layer mask controls which parts of a layer you can see. Use one to hide a background, let a photo show through a shape or correct an edge after making a cutout. Photo Studio has a free Layer Mask Brush for painting a mask. It also lets you turn a selection into a mask when you already know exactly which area to keep.
Masking lets you refine the same layer as you work. You can paint over an area to hide it, reveal part of it again and disable the mask to inspect the whole layer. This guide uses a shape over a photo to show the brush controls, then explains how to apply the same idea to a photo cutout.
Step 1. Open Photo Studio and load a photo
Go to the Free Photo Editing Software homepage and choose Photo Editor or Open Photo Editor. In Photo Studio, choose Open a photo and upload a JPEG, PNG or WebP. Use Open photo in the top bar if the editor has another document open. Start with an image that has a distinct subject, such as a bicycle against a wall or a notebook on a tabletop.
Choose Fit to see the whole frame. Identify what you want visible after masking. If you want a shape to appear behind part of a photo, think about where the two layers overlap. If you want a cutout, decide whether the small openings inside the subject should stay visible or show through to the next background.
Step 2. Select the layer the mask should affect
For a practice edit, choose Add shape, select Rectangle and place it over part of the photo. Open Layers and select the rectangle. In the layer stack, rows higher up appear in front of rows below them. Keep the rectangle above the photo so that hiding part of the rectangle reveals the photograph underneath.
Check that the rectangle is visible and unlocked. Click Paint mask in the layer controls to select the mask brush. You can also choose Layer Mask Brush in the toolbar or press M. Look at the target name in the tool options before painting. If you want to mask the photo itself, select Photo instead.
Step 3. Hide part of the layer with the brush
Set Action to Hide pixels. Increase Size until the brush ring covers a reasonable part of the area you want to conceal. Leave Opacity high for a clear opening, and use a lower value if you want the layer to remain faintly visible. Hardness affects how sharply the brush edge changes from hidden to visible. A softer edge works well when the transition should be gradual.
Paint a short stroke over the rectangle. Where the mask hides the rectangle, the photo underneath becomes visible. If you mask the only visible layer, the same stroke can reveal the checkerboard. The checkerboard indicates transparent space in the composition.
Start in a broad area, then zoom in and use a smaller brush near details. For a shape partly hidden by a bicycle wheel, a broad first pass removes the middle of the overlap. A smaller pass follows the rim more carefully.
Step 4. Reveal an area that was hidden by mistake
Change Action to Reveal pixels, then paint where you want to bring part of the layer back. The brush restores visibility within the area you paint. Reduce the size near the edge so you can repair a narrow strip without changing the entire mask. For a more exact correction, zoom in before trying to trace a thin line.
Use Disable mask in Layers to see the full layer, then choose Enable mask to return to your work. This comparison helps you catch an area you covered by accident. Clear mask removes the mask from that layer. Choose it when you intend to begin that layer's mask again, or use Undo when only the last stroke needs correcting.
Step 5. Create a mask from an existing selection
For a cutout of a notebook, choose Polygonal Lasso and click its corners. Finish the polygon, then check the selected outline. On a flat backdrop with a clear colour difference, Magic Wand may be a quicker way to select the background. Use the tool that follows the edge most accurately for the photo you have.
Select the target layer in Layers. Choose Keep selected pixels if the selection surrounds the notebook. Choose Hide selected pixels if the selection covers the unwanted background. When the mask is applied, use Select → Deselect pixels. That lets you inspect the result without the selection line and gives the mask brush room to work beyond the previous selection boundary.
A selection can also act as a temporary boundary for the brush. For example, select the front of a package before hiding part of a graphic that overlaps it. Paint the mask across the overlap and let the selection limit the stroke. Deselect when you need to work on another part of the layer. If a later edit still seems confined to that same area, check whether the selection is active before adjusting the brush size or repainting the mask.
Step 6. Inspect the mask with the intended background
At high zoom, check the edge for old background colour, gaps and jagged traces. Then use Fit to see whether the edge looks convincing at a normal size. For a cutout with transparent surroundings, consider placing a contrasting shape below the cutout layer temporarily. It can reveal pale fringes or missing areas that are easy to overlook against the checkerboard.
If you find a gap, check that you still have the correct layer selected before using Reveal pixels. A stroke made on a different layer changes its own mask. After checking, hide the temporary shape if you need a transparent export, or leave it visible if it is the background you intend to deliver.
Step 7. Download the masked image
Choose Download image for a PNG. PNG is useful when the hidden area needs to stay transparent. Use Download options for a different output size or format. Open the download to confirm that the visible layers and transparent areas match the composition you checked.
If you will need to refine the edge later, choose File → Download project as well. The editable project keeps the layer and its mask together, so you can reopen it and continue painting.