I am Seamus O'Neill. I mostly work under my READY STEADY CODE Scratch persona. In 2014 I gave a presentation to the team of developers in Serif, Software Ltd.2014 in Nottingham, UK. It was their first introduction to Scratch and they were intrigued that their DrawPlus and PagePlus software was compatible with the SVG filetypes used in Scratch. I used their DrawPlus to design the Ready-Steady-Code vector grids that are now available in the Scratch Backdrops library as Xy-grid-20px and Xy-grid-30px. The Serif Animals were supplied free with DrawPlus and Page Plus. So I am able to make these extra sprites available courtesy of Serif software at www.serif.com
