1.

To start, open the Photoshop CS program and invoke the file browser by choosing File -> Browse from the menu bar.

2.

Use the File Browser to navigate to the Photoshop samples folder. Open the Fish image by double clicking on the thumbnail in the file browser. When the image opens, close (X) the file browser. Your Photoshop CS screen should look something like this.

3.

Right click on the document window title bar and choose Duplicate from the pop up menu. In the dialog box that appears, name the copy Practice8.

Click the OK button to create the copy. When the copy opens, close (X) the original image.

4.

Take a look at the Layers palette for the image.

In the layers palette, select the Liquefied Bubbles layer (so that it is highlighted in blue).

Next, click on the small empty square just to the left of the ColourfulFish layer. You should see a small section of chain appear where you clicked.

The small chain indicates that the layer has been linked.

To test this, select the Move tool from the toolbox, and drag your mouse pointer over the image. You should be able to move the swirling liquefied bubbles and some fish together around the image window.

5.

Now that you have linked the two layers, it is time to merge them.

To merge the Liquefied Bubble layer and the ColourfulFish layer, click the arrow at the top left of the Layers palette to display the Layer menu.

In the Layers menu, click the Merge Linked option to merge the two layers into one.

6.

Now you will see the ColourfulFish and Liquefied Bubbles layers merged into one layer.

This will make the file size slightly smaller, but you will not be able to separate the merged layers.

You will now be able to perform edits on the combined data all at once by editing the merged Liquefied Bubbles layer.

7.

For the next step, you will flatten the file. To do this, first make sure that all of the layers are visible. Next, click the small arrow at the upper right to expose the layers menu.

In the layers menu, choose Flatten Image to combine the layers and remove transparent pixels.

If there were hidden layers in the image, you would see an alert asking if it is OK to remove them; but since you set all layers to visible, this will not be the case this time.

8.

After the image is flattened, you will see only one layer in the layers palette. This one layer will contain all of the information for the image.

9.

Look carefully in the lower left of your screen at the status bar. You should see a pair of numbers displayed that look like the following.

The first number indicates the file size of your image as seen on your screen (with no layer information). The second number indicates the size of the image file including its layer information. Because this image was flattened, both numbers are the same.

Now, choose File->Open Recent->Fish.psd from the menu bar. This will open the original image with all of its layers preserved.

10.

Make the original Fish image the active image by clicking on its title bar. The numbers in the status bar should now look like this: Doc: 602.3K / 6.48M

Once again, the first number is the basic image size without all of the layer information, and the second number is the file size including the data for the separate layers.  The size of the image file including layers is more than 10 times the size of the image file without the layers. This is indicative of the kind of space savings you can get when you flatten an image.

11.

Close (X) the original image, and use File->Save As to save the Practice8 image in your practice folder as a PSD file. When you have saved the file, use the Ctrl +Q shortcut to close Photoshop CS.