For some weird reason, I’ve been screwing up canvas size adjustments for ages. I really don’t know why this is. It’s probably got something to do with impatience. When working with canvas size in Adobe Photoshop, you need to know what you’re doing and you need to take the time to do it correctly. That’s why I feel a post like this is important. It lays the ground rules for properly using some of the tools available that will enable us to size and resize the canvas in Photoshop.
In today’s post, I’m going to work through three different scenarios that will give you a handle on how to effectively adjust the size of the canvas in Adobe Photoshop. Once you’re finished reading through this post, I hope you’ll agree that this type of thing really isn’t challenging at all. It merely takes an understanding of what a very small number of things mean. Once there’s a grasp on them, the rest is as easy as pie.
What is Canvas Size?
Before I begin, I figured that I’d try to explain what canvas size actually is. Let’s say that you open a photograph into Photoshop that measures 6 inches by 6 inches. The moment you open that image, Photoshop sets both the image size and the canvas size to 6 inches square. If you change the image size to 5 inches, the canvas size also changes to 5 inches. If you now want to create a border around the image of, say, 1/2 inch, you’d set the canvas size to 7 inches square. In this case, the photo size would stay the same, but a border would appear around the image that measured 1/2 inch thick.
So, think of it this way. You are standing in a room holding an actual paper photograph in your hand. That photo is 6 inches square. In front of you there is an actual physical painter’s canvas. It measures 7 inches square. Using scotch tape, you stick the photograph onto the canvas. There you have it. A 6 inch photo on a 7 inch canvas. Understanding the difference between the two is the most challenging part. Once you do, the rest is smooth sailing.
I do want to mention one nuance before I go any further. If I were to set up an image and canvas like this inside Photoshop and then export the file, the output would be a 7 inch square image. Canvas size is only a term used inside of Photoshop. If I were to open the saved file back into Photoshop, the new image size would be the 7 inches. From there, I could reset the canvas size again and play around as much as I want to.
Adjusting Canvas Size, the Long Way
For this post, I’ll be using a cropped version of this photo:
I cropped it square, so the demonstrations in this post are as straightforward as possible. The last thing we need at this point are varied dimensions.
Now, as it stands, the image I’ll be working with measures a perfect 6 inches by 6 inches. Let’s say I would like to add that border I spoke of earlier in this post. I want to see a white, 1/2 inch border all the way around the photograph. How would I achieve this goal?
To kick thing off, I’ll head up to the Image > Canvas Size menu item and click on it.
After I click that, I’ll see the Canvas Size dialog box appear.
Inside this dialog box is where it all happens. If you take a close look at it, you’ll see three sections. The first section deals with the image’s current dimensions. The second one deals with the dimensions you’d like to change the canvas size to and the third section deals with the color of the canvas. For now, I’ll talk only about the second and third sections.
Since I’m already dealing with inches, I’ll change the first drop-down box in the second section to Inches, as opposed to Percentage. I only need to change one because once I do that, the other will change to Inches automatically.
After that, I’ll keep the Relative box checked, because I want the units I place in the Width and Height fields to be relative to the existing dimension.
The next area I’d like to talk about is extremely important. The settings in this area instruct Photoshop to place the exposed canvas where the user wants it to be seen. If you look closely at the Anchor area, you’ll see it sort of looks like a tic-tac-toe board.
Currently, the anchor sits directly in the center square. This means that any change I make to the canvas width or height will be applied from that center position. Let’s see what the outcome would look like if I added 1 inch to both of these fields with the anchor point remaining at the center.
As you can see, the photo size has remained at 6 inches square while the canvas size has changed to 7 inches square. Since I added 1 inch to each of the width and height variables, 1/2 inch was added all the way around the photo in a uniform fashion. That’s fairly straightforward.
I’ll try this same experiment again. This time, I’ll move the anchor point to the left by one square, while keeping the width and height the same as the previous example.
Let’s check out the result.
This is interesting. In this case, the entire inch was added to the right side while a 1/2 inch was added to the top and bottom. The result is the same though in that the canvas is 7 inches square.
I encourage you to open up a sample photo and experiment with this tool inside of Photoshop. There are tons of variations and the only way you’ll truly get a handle on them is to experience them for yourself.
The last thing I’d like to talk about in this section has to do with canvas color. If you look at some of the previous screenshots, you’ll notice a bottom section inside of the Canvas Size dialog box. This section is called Canvas Extension Color and it’s probably the most simple of all the areas to learn and understand.
In the examples I gave above, you saw a white border. The only reason that happened to be was that, by chance, I had the background color in the color picker set to white. If I wanted a different exposed canvas color to appear around the photo, I could have set that color in this bottom section.
If you look at the above screenshot closely, you’ll see that there are a few different preset choices for you to choose from. In the drop-down box, there are Foreground, Background, White, Black, Gray and Other. If you click one of those selections, you can alter the color of the canvas. Also, if you look directly to the right of the drop-down box, you’ll see a small white square. If you click that, the color picker will appear, giving you the opportunity to select a custom color of your liking.
Changing Canvas Size Using the Crop Tool
What I gave you above was the longer version of how you can change the canvas size of a document inside of Photoshop. Hopefully, this section will be more brief.
Below, I think I’ll quickly run through a short project that will help you visualize how I might want to use the Crop Tool to resize the canvas around our demo photo. Pay attention because I’m going to move fast. If you have any questions after I’m finished, please ask them in the comment section below.
First, I’ll select the Crop Tool from the left vertical toolbar. This will highlight the image with the dashed markings of the tool. After that, I’ll click on the drop-down box that’s located in the options bar above the photo. I’ll select the 1 to 1 ratio, just so the new canvas size remains a perfect square.
Next, I’ll use the keyboard Ctrl+- to shrink the view of the image a bit, which will help me as I drag the Crop Tool handles. From there, I’ll drag the corner of the tool outward and I’ll press Enter on my keyboard to apply the crop.
As you can see, the canvas is transparent. The good news is that the canvas size was changed. I don’t know its exact size, but that’s not a concern for me right now. If it was, I would have used the previous method where I can be as exact as I want. This is more of the freehand approach.
Since I would like a colored canvas, I’ll create a new bottom layer over in the Layers panel.
Next, with the new layer selected, I’ll select the Paint Bucket Tool from the left vertical toolbar and then select a color from the Color Picker. Finally, I’ll click inside the transparent canvas area, which will fill that area with whatever color I chose inside of the color picker. In this case, I chose white.
Okay, I’ve gotten this far. There’s only one thing left to do and that’s to center the image. To accomplish this, I’ll go back over to the Layers panel and select the image layer. Then, I’ll select the Rectangular Marquee Tool in the left vertical toolbar. Next, I’ll use the keyboard shortcut of Ctrl+A to select all, which will outline the entire canvas area with some marching ants. Those ants indicate the selected area.
To center the image, I’ll now select the Move Tool from the left vertical toolbar, which will expose an options bar. Inside the options bar, I’ll click on the Align Vertical Centers and Align Horizontal Centers. This will align the selected layer inside the canvas area.
And here’s the selected result.
I have to say, that’s pretty cool. If I don’t need to know the exact dimensions, this may be the way to go. To un-select the canvas area, simply choose the Rectangular Marquee Tool again and click inside the workspace.
Trimming the Canvas
While I thought the previous section was going to be shorter, it sort of wasn’t. My goal for this section is to really stay brief. Let’s see if I can do it.
Let’s say I’d like to remove the outer border from this image. You know, the one I just created by expanding the canvas size. Well, instead of undoing what I just did, I can simply trim it away by using an extraordinarily easy tool to use.
To trim away a canvas, I’ll head up to the Image > Trim menu item and select it.
After I do that, the Trim dialog box will appear.
Since I’d like to remove all the canvas from all around the photo, I’ll choose Top Left Pixel Color from the top section and Top, Bottom, Left and Right from the bottom section.
When finished, I’ll click the OK button and watch in amazement as the canvas disappears.
And that, my friends, is how you trim the canvas area away from a photo.
In closing, I must tell you that I was going to add one more section. As I wrote this post though, I decided that three great tips were fine. The fourth is kind of complex, so I think I’m going to keep that one for a separate post all to itself.
Anyway, I hope you got something from this post and learned a bit more about Photoshop. If you have any questions or concerns, please leave them in the comment section below. As always, thanks for reading!