Adjusting the transparency setting to reveal the background part of the image.
Figure G: Change the transparency setting to expose the original picture, just a bit.

Have you ever been handed a busy picture to work with in a PowerPoint presentation? As a rule, a busy picture isn’t a great visual for a Microsoft PowerPoint presentation. You know as soon as you see the picture that you must tone it down a bit. One way to deal with a busy picture is to hide it and expose parts of the picture on which to focus. Doing so is an easy process that even a beginner can implement.

In this tutorial, I’ll show you how to use shapes and a “mask layer” to expose parts of an underlying picture.

I’m using Microsoft 365 on a Windows 10-bit system, but you can use earlier versions of PowerPoint 2013. PowerPoint for the web will display the slide, but you can’t create it in the browser version because the Merge option isn’t available.

You can download the Microsoft PowerPoint file for this tutorial.

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Insert a picture into PowerPoint

The first thing you need is a picture—a busy picture. If you have one, use it. Otherwise, insert the picture shown in Figure A, which is from Microsoft stock and freely distributable via Common License.

Figure A

Writing of formulas on a chalkboard.
Insert a picture into PowerPoint.

To insert a picture from stock, select a blank slide. Click the Insert menu, and in the Images group, click the Pictures dropdown and choose Stock Images. In the resulting window, find a busy picture. Click the picture to select it, and click Insert.

The next step is to pinpoint the pieces of the picture you want to completely expose.

Pinpoint pieces of the picture in PowerPoint

This next step might not seem to make sense because instead of exposing parts of the picture, we’re covering it. Later, it will all come together and make sense. For now, choose a shape to position over the parts of the picture you want to expose (Figure B).

Figure B

A blue circle over an image of writing on a chalkboard.
Cover what you want to expose with a shape.

To accomplish this, click the Insert tab. In the Illustrations group, click the Shapes dropdown. You can choose any shape, but this time, choose an oval. While holding down the Shift key, click and drag to position and size a circle. Repeat this process, adding more shapes (Figure C). Don’t add too many because the result will be just as busy as the original picture.

Figure C

Four blue circles of varying size over writing on a chalkboard.
We’ll expose four pieces of this picture, so we need four shapes.

With the pieces temporarily obscured by shapes, it’s time to add the mask layer.

Add a mask layer to a PowerPoint slide

There’s no such thing as a “mask layer” in PowerPoint. I’m using the term to add meaning to what this step is about. We’ll add a rectangle shape that’s the same size as the slide. Then, we’ll send it to the back, so the shapes are on top. I’m going to change the color of the rectangle so you can see both layers, but this step isn’t technically necessary.

To insert a rectangle, click the Insert tab. In the Illustrations group, click the Shapes dropdown, and choose the rectangle. Click and drag to position the rectangle over the slide. From the contextual Shape Format tab, click the Shape Fill dropdown in the Shape Styles group and choose a color other than blue, so the circles will show up later. In the Arrange group, click the Send Backward option four times to expose the four blue circles (Figure D).

Figure D

Blue circles on an orange background.
Add the mask layer behind the blue circles.

Now, we’re ready to expose the original picture under the mask layer, the orange rectangle.

Use Merge to expose the original picture

If you’re not familiar with this next feature, you’ll be surprised at the results. We’re going to merge the blue circles and the orange rectangle to “cut out” the blue circles.

To accomplish this, select the five objects: the rectangle and all four circles. Be sure to select the rectangle first or the effect won’t be the same. To do so, click the rectangle, and then hold down the Ctrl key while you click the circles. Doing so creates a multi-object selection. Then click the contextual Shape Format tab. In the Insert Shapes group, click the Merge dropdown, and choose Subtract (Figure E).

Figure E

Using the subtract merge shape in powerpoint to reveal pieces of the image in the background.
The merge option allows you to “cut out” pieces of the mask layer exposing the picture underneath.

Along with the original picture, we’ve exposed a bit of the bare slide, which is an easy fix. Select only the orange rectangle and move it to the right a bit, exposing the edge of the slide. Right-click the slide, and choose Format Background. Doing so displays the Format Background pane.

Expand the Fill section if necessary. Then, click Solid Fill. From the color dropdown, choose a charcoal black (Figure F). Drag the orange rectangle to its original position.

Figure F

Choosing a background color in PowerPoint.
The slide background should match the original picture’s background.

You could format the slide background at the beginning of this process, but it’s good to know that PowerPoint is flexible enough to let you do it later. If you find later that the color isn’t right, repeat the process until it is.

You could change the color of the rectangle and stop here, but let’s go a step further and expose the underlying picture just a bit. I think that you’ll agree that the extra step is worth it.

Make the rectangle transparent in PowerPoint

In this last step, we’re going to change the color of the mask layer from orange to charcoal, to match the original picture’s background. Then, we’ll use a transparency setting to expose just a bit of the original picture.

To accomplish this, click the contextual Shape Format tab. Click the orange rectangle and choose charcoal black from the Shape Fill dropdown. Try to match the color you used earlier for the slide’s background, but if it’s off a bit, don’t worry about it right now. You can change it when you’re done with this step. Right-click the rectangle’s background and choose Format Shape. In the Format Shape pane, enter 15 as the transparency setting (Figure G).

Figure H shows the slide in Slide Show view. It’s a neat technique that’s easy to implement.

Figure H

an image of writing a chalk board with circles highlighting certain parts
Display the slide in Slide Show.