Even though there is only the one image, I put it in a gallery because it is oversized.
This was done for the Minerva McGonagall Fest of 2015. A Fest operates a bit differently from an Exchange. In an Exchange, everyone participating submits a certain number of prompts, either for art or fic, the moderators collect them and assign each participant another participant’s prompts. Each participant then is supposed to choose something from the list they've been assigned, and produce either art or fiction (or craftwork, that is also sometimes done for an exchange) as a gift for the person whose prompts those are.
In a Fest, everyone submits prompts (again, usually either for art or fic) and the moderators collect them. When the prompt submission period is over, then, rather than assigning prompts to the participants, the list is posted for the participants to “claim” a prompt that they would like to produce. In many fests, one can even claim one of one’s own prompts if one likes.
And, of course, all fic and art produced for an Exchange or a Fest needs to be submitted to the moderators by the deadline, who then organize it and upon the announced start date begin posting the submissions (anonymously), one or two a day, until they have all been posted. A week or so after all of the posts have been made, a “reveal” list is posted letting everyone know which participant created each submission.
Both are very popular in most online fandoms.
Well, I signed up for the Minerva Fest and one of the prompts was for an illustration of Minerva and the other teachers in the Staff Room. I claimed it, got my claim accepted, and built the Hogwarts staffroom.
During the reveal of the Hoggy-Warty Xmas Fest — which I also partcipated in, one of the reviewers said that she wished she could blow up an illustration and print it as a poster. Given some consideration I decided that it seemed doable within reason. Most of my illos start out at 300ppi which is too big to post as an image on the internet, but large enough to export at a printable resolution in something like poster size.
So went back and I did exports of the two illos I built for that year's Hoggy-Warty Xmas Fest, as well as this one. I sized them to fit on an Architectural C sheet. People were welcome to download and take it to Kinko’s or some other service bureau to get it printed. They'd need an unziping utility. They’re all compressed files, even if they don't compress very much. They're all .jpg, so most software ought to be able to handle them. I left a bit of a margin and one might have to trim some excess.
However, I never heard whether anyone ever took advantage of the offer. So I've not repeated it in this iteration of the site. If you would like me to replace it, let me know. I stil, have the files, and adding a link for download wouln’t be difficult.