The classic yellow-and-white “danger!” tape is visually apparent and can be quite useful for indicating that an area is hazardous or off-limits. However! There are two problems:
Fig 1: The classic “danger” tape. But you might not know it if you couldn’t read English!
First, the “danger” text is specific to one language.
Second, the colors of the tape are culturally specific; maybe in some far-off island, yellow-and-white tape is used to indicate “here is a delicious free chocolate rabbit for the annual chocolate festival.”
We can create a language- and culture-neutral design for the tape—something that will indicate “danger!” to all humans, without requiring explanation.
Specifically, the tape will be designed to have an infinitely extended row of deadly pointed teeth, which are a relatively universal sign to indicate that a possible hazard exists within. Additionally, the tape could have periodic sections of “angry eyebrows” and glaring eyes to really drive home the point. (Admittedly, despite the universality of human facial expressions, “cartoon angry eyebrows” are probably not a symbol that is understood across all human societies.)
Fig 2: The “monster teeth” danger tape. Note the blood-stained shark teeth and angry eyebrows.
Fig 3: Artist’s rendition of the muppet-like monster face whose presence is evoked by the design of the tape. May be insufficiently menacing in current form.
PROS: Would be especially useful in countries with many official languages, saving the trouble of translating the text into each language.
CONS: May be culturally insensitive to shark-toothed monsters.