It's becauase the argument passed to the chr() method is out of the range. Want to learn more Python for Data Science? Head over to DataCamp and try their free Python Tutorial
The second product used in this project is Liquitex pouring medium. This is a low viscosity (very fluid), clear, and high gloss acrylic medium. It is about the consistency of warm honey; quite sticky also. It can ben used with your regular heavy body paint to make them flow easier, and create cool dripping effects.
Gel medium is an acrylic product. It comes in Heavy, Soft, and Regular and has a variety of finishes, Matte, Gloss and Semi-gloss. The basic use for these is to build texture in paintings by mixing them with acrylic paint. If you add a small bit of it to your paint it will also extend the drying time. The Soft gel is the medium that is most often used by paper artists. It can be used as a glue for collage and it is also used to make photocopy transfers.