The thresholds
Allow at least:
- 0.25 pt for a positive rule (dark line on a light background).
- 0.5 pt for a knocked-out or reversed rule (light line on a dark background, or multicoloured).
Avoid “hairline” rules
“Hairline” weights defined without a real value can print unpredictably — sometimes almost invisibly. Always give your lines an explicit numeric weight.
Check before you send
- Positive rules ≥ 0.25 pt
- Knocked-out rules ≥ 0.5 pt
- No undefined “hairline” weights
Frequently asked questions
Why did my thin border disappear?
It was probably below the threshold, or set as a hairline. Give it a weight of at least 0.25 pt (0.5 pt if it is light on a dark background).
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