Table of Contents
The article will explain how to create a polyptych preview image using Photoshop.
There are two methods, depending on your source image. The first section will explain how to take one image, divide it into multiple separate images ready to use for the preview image (and ready to be used as source images themselves), and then how to combine the separate images with a transparent background so it’s ready to upload to the site.
The second section will stand with several separate panel images, and show how to combine then with a transparent background so it’s ready to use as the preview image for the polyptych product.
Creating a Polyptych from One Image
What I’m going to be doing here is showing you how to divide your image into multiple parts using Photoshop. I’ll be keeping it simple with my demonstration, turning a wide panorama into three equally sized pieces.
Splitting the Source Image
We start by opening the source image in Photoshop.
What we need first is the resolution of the image. To find this click on Image, and then on Image Size.
As you can see here, the size of my image is 8193x1953. These values are what I’ll be performing my calculations on, in order to work out where to modify my image to create the source images for each panel of the polyptych.
What I’m going to do now is to perform some maths to determine the size of each panel. How you will do this for your images will depend on the size of your source image, and how you intend to split it up.
In my case, I need to divide my source in thirds. One third of the width of the image is 2731, a value which I’ll use later in this section.
I’ll start by clicking on Image, and then on Canvas Size.
This will open the dialogue window which is where we will create our first individual image.
Click on the unit of measurement (in my case it is in cm) and change it to Pixels. (Changing one will change it in both boxes)
For the first part, I’m going to be removing the right two-thirds of the image. What’s left will be the first of the three source images.
To do this, I’ll resize the canvas. This will effectively cut off the right side of the image at the value I enter as the new width. I mentioned before that a third of the current width is 2731, so I’ll put that into the width field.
I’ll also change the anchor point from which I will be measuring the image by clicking on the second box down on the left side. This will tell photoshop that when it’s counting those 2731 pixels, they should be starting from the left edge of the window.
A new window will pop up warning that the selection is smaller than the current canva size, but this is what is intended. Click on Proceed to modify the image.
You will now see the cropped left image.
We can now save this part of the polyptych. Click on File, then on Save As.
After selecting the location to save the file, put in your filename and select your format, and then click Save.
As I’m saving mine as a PNG I have one more box to click through.
Now we’re going to close this image. Click on File, and then on Close.
For the second piece, we can re-open the original image again.
We’re now going to open the Resize Canvas dialogue again. Click on Image, and then on Canvas Size.
And change the width measure to pixels.
Now enter 2731 as the width and leave the Anchor in the center, then click on OK.
The canvas dialogue box will appear, so click Proceed again.
And now the center piece is complete. Save this alongside the previous piece and then close it.
Now to re-open the original image for the third and final time.
Open the Canvas Size dialogue, and repeat again, but this time set the Anchor on the middle-right of the 9 boxes.
This will create the third and final piece. Save this, and close it.
Now all three pieces are ready to be used as source images for the component panels. Next I will show how you can use these images to create the transparent preview image which you will use for your polyptych product.
Creating the Preview Image
Now I’ll show you how to create the preview image, which will have all three panels combined in one image, separated by transparent sections which will ensure the image works correctly when viewed in the Wall Preview or Live Preview.
First I’ll open the three panel images, and then I’ll create a blank image at a resolution which lines up with the size of all three images combined, plus an extra margin for the gap between each panel.
In this case the source panels came from an image that was 8193x1953. As this is designed to be 55x13 in size (at a resolution of 150DPI) I’ll add an extra 2 inches (or 300 pixels) to the total width, making it 8493x1953.
Now I’ll switch to the left-most panel, click on Select, and then click on All.
Then click on Edit and Copy.
First I'll switch back to the blank polyptych image, click on Edit, and select Paste.
This will drop the image in the middle of the blank space.
What you will do now is select the Move tool, then click on the image and drag to the left. It should “stick” to the edges when it is close enough to them, which will make it easier to align it against the left edge of the background. (You can see visual indication of that in my screenshot as the mauve effect around the outline of the background)
Repeat this process with the right panel.
And now it’s time to add the center panel to the background. This panel will appear in the center, and won’t need to be re-positioned.
Let's save this image. Click on File, then on Save As...
Enter a filename for the backup, and click on Save.
Click on OK on the Maximize Compatibility window.
Now to create the PNG version. This will be the preview image which is uploaded to the site and attached to a Polyptych product. (You can’t create JPGs for polyptych images, as the wall preview requires that the images have a transparent background and only PNG supports this)
While there’s a spacious 100mb limit for images in an art print store, the limit for an image in a standard store (where the polyptych products are located) is a much lower 20mb. This is because detailed high-resolution images are needed for art prints, but standard store products are only going to be displayed on the screen of a computer or mobile device.
Because this is going to be in a standard store, it doesn’t need to be as large as the component pieces, and in this step I’ll show you how to resize it.
First click on Image, and then on Image Size.
This will bring up a dialogue window showing you the resolution of the image.
We really don’t need it to be this big, so let’s make it smaller by putting in a width of 1500. The program will automatically change the height to match.
After clicking OK the dialogue the image will appear to have shrunk, which it has.
While the image is now smaller, it's not that much smaller. You can make it appear larger again by changing the enlargement value in the bottom left of the window.
Now we can save the smaller image as a PNG. Let’s start this by clicking on File and then on Save As again.
Click on Format, and select PNG, then on Save.
Make sure Interlace is set as None, then click on OK.
Then you'll have the completed preview image. Once you've added it to the polyptych product in your standard store, it should render correctly on the preview screens with the wall background visible through the transparent sections of the image.
Creating a Polyptych from Multiple Images
If you are creating a polyptych from several separate images this will be a simpler task. All you are doing is combining those images on a transparent background.
Creating the Preview Image
For this I’ll need to know the exact resolution of each of the images I’m creating the preview from.
I’ll start by opening all three in Photoshop.
Starting with the first image, I’ll click on Image, and then on Image Size.
This will bring up the dimensions of this image. I’ll make a note of this so I’ll be able to compare the three sizes.
I’ll repeat this for the second image.
And for the third.
Now to compare the sizes.
As you can see, the third image has a slightly different resolution to the first two.
What I’m going to do is to resize the third image so it has the same height (and as a result, around the same width) as the first two. This will make it easier when creating the preview image. (I’m matching the height as the display will have the three images displayed side-by-side. If I was displaying them vertically, each one above the next, I would instead match the width)
To change the height, I will again go to the third image and open the Image Size dialogue.
What I will do is replace the height of the image (3125) with the height shared by the other two images (2976). Then I just need to click on OK and the image will be scaled down to match the other two pieces.
Now it’s time to create the blank preview image. For this, the resolution will be the height of the images and three times the width of the images, plus some extra width to accomodate the distance between the panels when they are hung on the wall.
First I’ll determine the space between each panel for the preview, and how many pixels that will be. Each panel will be about about 24” wide when printed, and I can determine about how many pixels each inch will be by dividing the pixel width (3968) by the inch width (24).
3968/24 = 165 (rounding to the nearest whole number).
I’m going to have 2 inches between each panel, so the value will be 2 inches multiplied by 165.
2*165 = 330 pixels.
So the width for the background image will be the width of the first panel (3968) plus the gap between the first and second panels (330) plus the width of the second panel (3968) plus the gap between the second and third panels (330) plus the width of the third panel (3967).
3968+330+3968+330+3967 = 12563
The height of all three panels is 2976.
So the resolution of the preview is 12563x2976 pixels.
I’ll enter these values, making sure the background is set to be transparent, and click on OK to create this image.
Now I have the blank preview ready to place the three images onto.
I’ll start by going back to the first image, which will be located on the left side of the preview. Click on Select, and then on All.
Now click on Edit and then on Copy.
Switch to the preview, and click on Edit and then on Paste.
This will drop the first panel into the middle of the preview image.
Select the Move tool on the left, and drag the image off to the left side of the panel. It will try to stick to the edges of the panel, so it should be easy to position it correctly.
Now go to the third image (not the second - that one will be copied last), and Select All and Copy again.
And then return to the preview image and select Edit and Paste again.
This will drop the third image into the middle of the preview image.
Click on the Move tool again, and drag this panel over to the right side of the background.
Now switch to the second panel, and Select All and Copy.
And switch back to the preview image, and click on Edit and then on Paste.
This will drop the center panel in exactly the right place.
Time to save this working file, before we shrink it down to a more appropriate size to be attached to the polyptych product. Click on File, then on Save As.
Now set the file type to Photoshop (*.PSD; *.PDD), and (making sure that you’re saving it in the right place) click on Save.
In the next dialogue that pops up, leave Maximize Compatibility enabled, and click on OK.
Now to change the size of the image. For all images in a standard store (which is where polyptych-type products are stored) there is a maximum of 20mb. But as this image is only going to be displayed on the screen and not used as the source for a print image the way art print store images are, it’s a good idea to reduce the resolution to a much lower size. I’d recommend below 1500 for the largest value, which in this case is the width.
Let’s click on Image, and then on Image Size.
Now in the dialogue that opens, change the width to 1500. The height should automatically change to keep the image at the same aspect ratio. Also click on resample image and change the setting to Bicubic Sharper. Then click on OK.
The image will now look tiny in the editor window, but that’s purely because it was zoomed out quite a bit for its much larger previous size. Let’s just move on, and click on File and Save As.
We’re going to change the filetype to PNG, and then click on Save.
In the next dialogue box check that Interlace is set to None, then click on OK and the preview image will be saved and will be ready to use for your polyptych preview image!