Virtually any medium can be used for advertising. Commercial advertising media can include wall paintings, billboards, street furniture components, printed flyers and rack cards, radio, cinema and television adverts.[from wikipedia]

Michael Masley is The Artist General.An artist who created warnings as art. All are prefixed with, "ARTIST GENERAL'S WARNING:"

In January 2014, the Capitol Area Development Authority (CADA) & the Sacramento Metropolitan Arts Commission (SMAC) received qualifications from local artists to be considered for CADA's "Capitol Box Art Project". Artists were selected based on past work and paid to create a design (or designs) that was transferred to vinyl, and wrapped around a City of Sacramento traffic utility box.[from capital box art website]

An art car is a vehicle that has had its appearance modified as an act of personal artistic expression. Art cars are often driven and owned by their creators, who are sometimes referred to as "Cartists". [from wikipedia]

Color (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the spectrum of light. Color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object's physical properties such as light absorption, emission spectra, etc. [from wikipedia]

Puzzles of ordinary objects with inobvious meanings.

Art discovered in randomly found textiles and wearable materials.

Discovered art out in the wilds

Found drawings and other art by children

Kites found aloft and fallen

Integers in various forms and combinations.

Posters and other collections of one-sheet sized art pieces on display.

The camera angle, or or viewpoint or how you look at it can reveal one thing or the other.

Slogans and found messages on sidewalks and other surfaces.

Sculpture is the branch of the visual arts that operates in three dimensions. It is one of the plastic arts. Durable sculptural processes originally used carving (the removal of material) and modelling (the addition of material, as clay), in stone, metal, ceramics, wood and other materials but, since Modernism, there has been an almost complete freedom of materials and process. [from wikipedia]

The shadow as a two-dimensional silhouette

From around the world

Plants sculpted or grown to appear like other things

Art made from or which contains trash