that will work to an extent,it should be the thick aluminium foil (more craft metal) and you only need straight lines but if the blade is chipped (very easy to do, you only have to knock them or use the wrong force and the end can chip) then no amount of sharpening will fix it.
for the hassle of tin foil on my mats etc not to mention it can go up inside the holder, it's easier and cheaper to just replace the blade.
I will only resharpen if I need to finish a project and cannot my the spares or I have no spares
Gaz
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Cutters: Phoenix Silver Bullet 18", Black Cat Cougar 18", Silhouette Cameo & Cameo 4
Software: SCAL 5 Pro, Inkscape, Gimp
Computer:IMac running Mojave