Patternfield

Yes you can upload mockups. We suggest you upload them as your secondary image to your main image. 

<a href="https://help.patternfieldapp.com/en/articles/6632176-post-a-non-occasional-non-seasonal-design">Post a non-occasional/non-seasonal design</a>

<a href="https://help.patternfieldapp.com/en/articles/6579345-design-information">Design Information</a>

<a href="https://help.patternfieldapp.com/en/articles/6579329-license-type">License type</a>

<a href="https://help.patternfieldapp.com/en/articles/6579380-collection-of-suggested-image-size">Collection of suggested image size</a>

<a href="https://help.patternfieldapp.com/en/articles/6673816-what-is-the-difference-between-yes-and-yes-buyers-campaign-only-at-the-marketing-section">What is the difference between "Yes" and "Yes - (Buyers Campaign Only)" at the "Marketing" section?</a>

Mockup