More clear and also partially clear flooring than you can shake the proverbial stick at here, listed under Building Material:
http://avenidasims.com/TheSims2/TheSims2DOWNLOAD.htmlMurano's reflective walls and floors items also at the booty:
http://paysites.mustbedestroyed.org/booty/tsr/murano/(millenium-reflectivewallsfloors.zip)
These can really slow down gameplay and stress a computer's graphics, depending on its specs.
Direct link to Merola's multi-painting:
http://www.simchaotics.net/Files/MerolaSims2/MultiPainting.htmOne-tile version (requires Pets, superseded for Free Time and up by the Sim Blender) by Inge:
http://www.simlogical.com/sl/Sims2Pages/Sims2_Feeling_MerolaPainting.htm.