There's currently no direct way you can include a size chart in your shop but there *is* a workaround as follows:

1. Create a new page and call it "Size Chart" -
Back office > Shop Settings > Info Pages > Create new

2. Go to http://imgur.com and upload the Size chart image you have using the 'Computer button' on the right

3. Once the image is uploaded, you'll be presented with a list of option on the right hand column.
Choose the option called: " HTML Image (websites & blogs)"
Copy the HTML snippet from the text box by highlighting it and then copy.

4. Return to your page in your back office.
Paste the HTML code you've just copied.

5. Click to save change and then you're done.

Optional!

6. You can add a link from any part of your site to the page you have created.
Adding links can be done like this:

In future, image uploads such as this will be available directly within your SupaDupa backoffice.
Hoping this helps for now.

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