So I've taken a screenshot and uploaded it to the workshop with my level. How do I make it the screenshot that appears when you search the level (in other words the opening screenshot?)

I strongly believe that the camera position in your PTI map is the only screenshot that will be displayed. I think it?s not possible to change it.

You need to upload your level from p2map_publish. There you can choose a custom screenshot. p2map_publish is in your Steam/steamapps/common/portal 2/bin folder. You'll find the workshop maps in steam/steamapps/common/portal 2/portal2_dlc2/maps/puzzlemaker.
I believe this is right, correct me if i'm wrong

UsCobra is right: if you want a custom screenshot use the publishing tool.
But personally I think it's a great system. You can easily pick out the PTI maps and generally speaking they are not as good as hammer maps. (there are a few exceptions, but generally speaking hammer maps are better)

Damn. Thanks anyway...

You can change or add images via the map's workshop web page. (On the right side, select "Add / edit images and videos".) It should also be possible to set up a slide show of multiple images.

(There is a "view in workshop" button somewhere in the in-game interface that takes you to this page, but I don't remember where exactly...)

@HMW - that's true, but I don't think you can change which screenshot shows up as the map's thumb in searches from the Workshop page. As far as I know, the p2map_publish tool is the only way you can do that.

Oh I see, you're right. It says you can upload additional images, besides the first one.
Welp, p2map_publish it is then.

(That being the case, it's extra annoying that the PTI-supplied image is just barely too small for the space it gets on the web page, resulting in that ugly 'banding' effect...)

Hi, I'm new here and I'm having trouble doing this myself. But what's strange is that I somehow did it before twice, but now I can't do it on my laptop for some reason.

http://steamcommunity.com/id/Unowninato ... ?appid=620

The one I want to change is Strange Cube.

Edit: Oh, and I went to SteamApps\common\Portal 2\bin\p2map_publish\resource, as someone else said, and it's just an empty folder.