You can set preferences for OEM and private label service by going to your 'Store' settings page and scroll to 'OEM Available': https://merchantshowroom.com/vendor-dashboard/settings/store/ .
Once you set OEM on your 'Store' settings page, when you create a product, this setting will automatically show on all newly created products. You can always over-write it by selecting another option when you create or edit your product.
Buyers will be able to filter search results based on this value, so if you do offer OEM or private label services, make sure you select 'Yes' in this drop down menu. However, if you do not offer OEM or private label services, do not select 'Yes', because that may upset the buyers. Buyers will be able to report sellers for false information. We require all vendors to be truthful in their sales on Merchant Showroom.