National Brand Computation Pad, Plain and 5 X 5 Quad On Back, 8.5 x 11 Inches, Green Paper, 100 Sheets (42382) https://www.amazon.com/dp/B0007LTJO0/ref=cm_sw_r_cp_apap_3fMUKPwE3UxRP
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National Brand Computation Pad, Plain and 5 X 5 Quad On Back, 8.5 x 11 Inches, Green Paper, 100 Sheets (42382)
https://www.amazon.com/dp/B0007LTJO0/ref=cm_sw_r_cp_api_Z1NCAbZGSMMRX
At my summer job working for World Class Electronics Company, I was introduced to <strong><em>National 42382</em></strong>. They used it to sketch out their cutting-edge designs. It's very nice stuff. I prefer to use it with a Pentel P205 mechanical pencil (link) and 0.5mm 2B lead.
But when that's not available I just grab a few sheets of copier paper and scribble with whatever Bic pen happens to be laying about.