How to make and sell maps compatible with Roll20

So I have been making maps using a software called inkarnate for a couple years now and I have recently been trying to sell maps and it seems like Roll20 would be a good place to sell them, I have a question, how does the selling process in Roll20 work? right now that maps I make have lights and stuff built in and are just a single jpeg file, are there like layers that I have to do or something. Also should the map have the grid in the file or do people add that after in Roll20? I also heard someone else talking about lining up doors, do you guys know what I have to do there, does the map have to be a certain resolution for that? Sorry if I sound clueless here, that's because I kind of am with Roll20, I am experienced in the whole mapping process but if anyone could help me with these questions about the Roll20 side of things that would be greatly appreciated.

Welcome and I think other people will come along to give better links, resources, answers. I can help with a start.  It's the Roll20 Marketplace and you have to apply and do their onboarding process and I think you can get a lot of specific answers in that process. They'll have an FAQ, a discord discussion group, other ways to get answers. In Roll20 Marketplace publishers/artists can sell Art Packs that have Maps that are JPG / PNG's. Alternatively or additionally you could create/sell a product-type called Modules or Add-Ons, this could include the Layers such as Doors/windows and dynamic lighting features. So you have both options and just the Art Packs containing JPG's is fine for your starting point. You can consider doing Modules/Layers later.  Many art-packs of maps cotain both Gridded and Gridless versions. A good tip is put the word (-grid, or -gridless) in the File Name and Title of each JPG so the user can easily decide which version they want to use. I personally use gridless maps (and I use Roll20 to overlay a grid if I want one, so for me it's preferred not to have grid showing on the map art). Including both versions is good anyway to add more value (more assets) to your Art Pack.  I highly recommend STEP ONE go click "Create Game" in Roll20 and make your own free blank empty tabletop. Drag-and-drop some of your maps onto the blank page there. Test the Page Settings, learn about the Pages Menu. 

(Caveat to this reply:&nbsp; I haven't sold anything on the marketplace myself, but I've read through the wiki and help files.) You'll have to become a "Roll20 Marketplace Partner": <a href="https://pages.roll20.net/partners" rel="nofollow">https://pages.roll20.net/partners</a> <a href="https://roll20partners.zendesk.com/hc/en-us/articles/10849171519511-Applying-to-Sell-on-the-Roll20-Marketplace" rel="nofollow">https://roll20partners.zendesk.com/hc/en-us/articles/10849171519511-Applying-to-Sell-on-the-Roll20-Marketplace</a> If you are only creating maps, there are two ways that they can be sold: as an Art Pack, or as a game Addon. (A module would include more than just maps.)&nbsp; <a href="https://roll20partners.zendesk.com/hc/en-us/articles/10269465622807-Building-Submitting-and-Activating-Roll20-Marketplace-and-Supported-Marketplace-Items#h_01H910BZTS11CM08KC09EZ8EBS" rel="nofollow">https://roll20partners.zendesk.com/hc/en-us/articles/10269465622807-Building-Submitting-and-Activating-Roll20-Marketplace-and-Supported-Marketplace-Items#h_01H910BZTS11CM08KC09EZ8EBS</a> As far as including grid lines or not, often marketplace maps will include both a gridded and non-gridded version. Art Pack Art packs are a group of images that get uploaded and sold as a group together. These would just be the map images, and wouldn't include Dynamic Lighting or anything else. Addons An addon can include more than just the map image, including Dynamic Lighting lines, doors and windows, etc.&nbsp; You basically create a blank game with the content you want to sell and that game can be submitted as an Addon. <a href="https://roll20partners.zendesk.com/hc/en-us/articles/10269636794519-Creating-Adventures-Rulebooks-and-other-Play-Aid-Content-Addons-Modules" rel="nofollow">https://roll20partners.zendesk.com/hc/en-us/articles/10269636794519-Creating-Adventures-Rulebooks-and-other-Play-Aid-Content-Addons-Modules</a> <a href="https://roll20partners.zendesk.com/hc/en-us/articles/10269613866135" rel="nofollow">https://roll20partners.zendesk.com/hc/en-us/articles/10269613866135</a>

Roll20's door and window features work easiest when they can snap to grid intersections. The "standard" square grid square is 70px, and maps are usually set to a scale of 5 ft. per grid square. That being said, when I prepare maps that will use Dynamic Lighting it's easiest when the walls align with the grid lines and door or window openings lie between grid intersections. Immortal Maps said: &nbsp;I also heard someone else talking about lining up doors, do you guys know what I have to do there, does the map have to be a certain resolution for that?

Giving walls some thickness, and making them center on grid lines definitely makes the dynamic lighting process easier.