Wheatpaste

 Wheatpaste glue is an easy to make, strong glue that is great for putting up posters in outdoors spaces. You can either paint your own posters on newspaper or other thin paper (perhaps using stencils!)

How to make Wheatpaste Glue:
Prepare 1 cup (2.4 dl) of very hot water. Make a thin mixture of 3 tablespoons (45 ml) of white flour and cold water (just enough to wet all the flour and make it liquid enough to pour). Pour the cold mixture slowly into the hot water while stirring constantly. Bring to a boil. When it thickens, allow to cool. Smear on like any other glue. For slightly better strength, add 1 tablespoon (15 ml) of sugar after the glue is thickened. After using a portion, reheat the remaining in a covered jar or container to sterilize it for storage or keep refrigerated. If wheat flour is not available, other flours will work.

Hit the town: Take a big paint brush or roller, along with squirt bottle or 1.5 gallon plastic trash can put in a messanger or book bag. Paint glue on the surface you want to stick the poster to, slap the poster into the glue, smooth the paper out, and then follow up with a final coat of glue over the top of the paper. Work quickly, without looking overly suspicious — teams of 2-3 people are optimal. Pick targets wisely: high visibility can be good but risky, near other posters may be safer and less likely to be torn down, think about who owns/maintains the space you're pasting.

Note: Do not do anything illegal. Obviously, that would be illegal.

This work done by Street artist "Swoon" is created using recycled paper and wheatpaste.