Assign a Preview image to your custom Page Layouts

There are quite a few good sites out there that provide steps for creating custom page layouts using the new SharePoint 2013 Design Manager, but none of them bring up how you would go about assigning a Preview image to your new custom Page Layouts. This is most likely due to the fact it's pretty simple to do once you know where to look for it. Anyway, these procedures assume that you've already created and deployed your new custom Page Layouts using Design Manager. Here goes...

Add the Preview Images to the Master Page Gallery

1. Using your web browser, open up a link to your Master Page Gallery (i.e.  http://SharePointWebApp/_catalogs/masterpage/Forms/AllItems.aspx)
2. Double-click on the en-us directory
3. Double-click on the Preview Images directory
4. Click on the Files tab
5. Under the New section, click Upload Document
6. Click Browse..., navigate to your first Preview file, and click on it
7. Click Open
8. Click OK
9. For Content Type, select Master Page Preview
10. For UI Version, place a check in the 15 checkbox
    
    
    
    
11. Click Save
12. Once the image is uploaded, click on the image list item and select Publish a Major Version
13. Click OK
14. Repeat Steps 5-13 for each Preview Image

NOTE:  If you don't publish your files as shown in Steps 12-13, your Preview images will appear as a red X when the user is looking at the locations where the Preview image is viewed

Assign the Preview Images

1. Navigate back to the home page of the Master Page Gallery
2. If you used the Design Manager to add your custom Page Layouts, you will click on the .html file associated with your first custom Page Layout and select Edit Properties (that is, if they are still associated with each other which is most likely the case...)
3. Locate the Preview Image section
4. Enter the URL of the file in the Type the Web address: textbox  (i.e. http://SharePointWebApp/_catalogs/masterpage/en-US/Preview%20Images/PreviewImageName.png)
5. Enter a user-friendly description in the Type the description: textbox
6. Click Save
7. Repeat Steps 2-6 to assign the Preview images to their resepctive Page Layouts

Verify the Preview Image of a custom Page Layout

1. Navigate to a page on your site and click Edit
2. Click on the Page tab
3. Under Page Actions, click Page Layout
4. Verify that your custom Preview image has been assigned (i.e. in my example, my custom Page Layout is TestLayout1 and it's based on the Article Page content type)