Birthday Song Music Notes Foil Quill Birthday Card Design. This is a single line sketch svg file. These single line designs are just that – made from one single line and perfect for using with a foil quill, engraving tools, sketch pens or infusible ink pens. These are not made for cutting. This design has 2 sizes included for a 5X7 card and an A2 card. The final thickness of the design will depend on the size of the tip or nib of the tool used. I have included a png file with these but it’s really just for viewing purposes. It’s not for tracing as that would create double lines so be sure to use the correct file your machine such as the SVG, DXF or EPS file.