Lay out both sides of the card and see it at true size before you order. Drag to move, use the corner handle to scale and rotate. The dashed line is the safe margin — keep anything that must not be trimmed inside it.
bleed, 2 mm out · die line · safe margin, 3 mm in and 1.5 mm clear of every perforation
Why this matters: the JSON records where each element sits in millimetres against the real die line, and which file it came from. Production rebuilds the layout at print resolution from those originals — a PDF stays vector — so nothing is printed at screen quality.