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Orders, capture guidance, license keys, and standards questions all go to rex@circlesfr.com. Include your chart serial number when it exists — it ties the print to its QC certificate.
Printed to order. Current lead time is confirmed with your order reply, then the chart ships in a rigid tube with tracking. Charts ship worldwide; duties and taxes for international orders are the recipient's responsibility.
Charts are printed to order. If a chart arrives damaged or its QC certificate values don't match the print, contact us within 14 days with photos and the serial number for a reprint or refund.
Every chart ships with a one-page certificate: measured white and black patch reflectance, print date, artwork version hash, and printer/media batch, tied to the serial number in the chart margin.
Keys verify offline and never phone home. Lost keys are reissued from your order record. Seat changes, academic pricing, and volume quotes are handled by email.
Standards note.
CircleSFR implements an ISO 12233-informed SFR workflow; ISO lists ISO 12233:2024 as the current edition. The chart is original artwork — not a reproduction of ISO or third-party charts — and CircleSFR does not claim ISO compliance or certification. The analysis pipeline documents which edition-informed techniques it uses (Hann LSF windowing, edge-angle correction, distorted-edge polynomial fitting).