Preferably, use a perforating wheel to cut,
but in lack of such, you can cut along lines with a scalpel,
taking care to not cut all the way to the edge.
Don't ask why but this bubble pipe is so German to me. Pipes and German thinking go hand-in-hand, was it Freud or Jung? I recall Freud smoked, but was it a cigar? Smoking is a bad thing, but at least this is not a cigarette! Imagine that! Cigarette bubble blower - weird! The pipe is a little more pseudo-academic I'd say, and a bubble pipe, well that just bursts all of the clichés. Bubble liquid goes in the one end of the pipe - dip the wand, lift & blow! The family owned Dr. Rolf Hein GmbH & Co. is the manufacturer of PUSTEFIX bubble toys since 1948 and they take pride in the quality of their bubble soap. I understand why. Pipe comes with soap on the side. Red and yellow pipes, they both work the same.