Once upon time I created poster for 25x38 cm printout @300dpi (in inches it makes something like 10"x15", but you can go higher, as you do not need 300 dpi for posters):
When I look at it now, then I'd do couple of things differently, but this was my first try to blend several images into one and I'm more-or-less satisfied with result.
And in case someone wonders, what the heck "ojankaivajat" means, then it's "trench diggers" in Finnish. All the riders are Finns and this poster is devoted to Finnish carving forum, leaded by Pokkis.
Feel free to print it out and put on the wall. But no commercial usage, please!
Just trying to master potential energy conversion to kinetic...