What image format were you saving your work in during development of the frames?

The image format I was saving my work in during the development of the frames was SVG File. In the dictionary,it is Scalable Vector Graphics (SVG) is a family of specifications of an XML-based file format for describing two-dimensional vector graphics, both static and dynamic. Simpler, an SVG File is a file which you can save and edit whenever you need to unlike saving it as a .png file, which you can only edit the whole picture, not separate components, making Inkscape a great software to create animation frames.