How do I ensure my design is only printed on the left chest?

The best way to lock a particular design to a specific print location is to use it to build a Featured Product. Featured products are manually and individually created products you can use to combine specific products, colors, and designs outside the automated shop creation process. 

If you'd like to use a design exclusively in the left chest position, you'll want to exclude that design from your catalog after uploading so it doesn't appear in your design library when your customers are designing products within the storefront.

Next, you'll use that design to create a featured product with Left Chest positioning selected.

This will ensure your customer can only purchase this design in a Left Chest position.

For detailed instructions on Featured Product creation, please review our tutorial on the subject here.