Smart objects  are special type of layers. They can be resized, rotated back and forth without ever losing quality on the way. That is already a huge advantage but there are so many other reasons why you must learn how to use them properly.

If you are doing any design work or any compositing where you have multiple layers and you’re making those layers or images larger and smaller, you will soon find out that the Free Transform is something you want to avoid. However, this is a destructive command. So, in the following canvass you can see two copies of a man.

We will start working with the one sitting to the right and you can turn on the visibility of that layer by clicking on the eye icon in the layers panel.

Now the Layer 1, the man sitting on the left is the one that is being selected.

On this Layer we will apply the Free Transform Tool.

To go ahead hold down the Option and the Shift key or Alt and the Shift key and we will make this a lot smaller. After making it smaller tap the enter or return key in order to apply that transformation.

When you apply that transformation you told Photoshop to throw away a lot of pixels. So, if you get to this point and you have changed your mind and want that layer to be larger what do you do? You use free transform again.  This time we will use the keyboard shortcut command or control + T. If we size this  image up by transforming it and scaling it while holding down the Option + Shift key  or Alt + Shift key, you can see that when you apply this transformation you have lost a lot of detail in the image.

So how can we avoid that?

We can avoid it by turning our layer into what’s called a Smart Object. Let’s go ahead and move to the Layer 2  layer.

Choose Layer > Smart Object and then Convert to a Smart Object.

Then we will use free transform on this layer and scale it down, just as small as the other one was. Apply enter or return to apply that transformation. Because it’s a Smart Object and you can see it with the icon on your layer panel.

When you use free transform again and drag up your image to resize it back up and tap the enter or return key to apply that transformation, you can see that you haven’t lost any detail.

In a nutshell a smart object is an embedded document within your Photoshop file, which preserves the original resolution and size of the layers content. You can compare what happens to a normal layer and the same layer turned into a smart object when you resize them twice.

So, although Smart Objects might make your image a little bit larger because when you transform your image smaller, Photoshop is still keeping hold of all of that higher resolution information. Think that  as the trade-off for having the flexibility to change your mind at any time and change your layout or change the size of your image is well worth the trade-off just a little bit of an increase in size. Another interesting technique is that if you duplicate a Smart Object, they will actually share the same source file.

Related Articles:

TUTORIAL: SMART OBJECT BASICS IN ADOBE PHOTOSHOP

Master the marvelous powers of Adobe Smart Objects

3 Essential Reasons to Use Photoshop’s Smart Objects