This is my new favorite Chicago streetart. The first piece I saw was this (above) at street level and I thought it might have been commissioned by the neighborhood organization or something (the empty building right next door is sporting a paint job that has the exact vibe). And the next piece I saw (below) at a playground on Lawrence Ave fed into that notion. The canvas for these pieces is the dour brown paint favored by the Chicago Graffiti Blasters and I even wonder if it might be the Blasters themselves trying to leave something more cheerful in their wake than their normal acres of dull brown.
The Lawrence Ave piece has the only thing like a signature or tag I've seen on these pieces -- a big 312 at the end of the piece, so that's how I'm refering to these (since 'blue liney things' sounds a little vague).
The next two pieces I saw, however, laid to rest the idea that this was anything authorized or official, as they were on classically graffitied roof-top walls within sight of the Brwn Mawr and, more recently, Sheridan El stops:
(detail from this piece)