Creating a 3D Model with Tinkercad - 3D Printing: Build your Own 3D Printer and Print your own 3D Objects - page 151

Figure 7.29 The imported object is now a printed object.
Importing an SVG file is a fun way to print three-dimensional objects that you or
someone else has drawn; just remember to keep it simple and have the object's
color as black on a white background and you're in business. But what do you do
if you only have a graphics program (such as Microsoft Paint) that can only save a
drawing as a JPEG or PNG file? Fortunately, you can take that image and convert
it to an SVG file using a free online tool.
Open a web browser and point it to http://www.online-convert.com and click on
the drop-down menu in the Image Converter box shown in Figure 7.30 .