Hello … just to let teams in the uk know … i recently purchased some polycarbonate (lexan) sheets from ebay and they are very good and cheap …
there are three thickness (all competition legal)
0.25mm thick : £2.95 per sheet (inc delivery)
0.5mm thick: £3.85 per sheet (inc delivery)
0.75mm thick: £4.25 per sheet (inc delivery)
they are really good - they are standard A4 paper size … so because the rule says 1x 12" x 24" sheet, you could in theory buy two of these and still be match legal
i hope this helps people
