EXPLAINED: Why Some Striped Backs Are Forbidden in Football Kits
- Delta L Rule: The "Delta L" rule dictates whether striped or half-and-half patterns on a football kit can continue behind player numbers, based on a contrast measurement between colors in the Number Zone.
- Contrast Measurement: If the color contrast in the Number Zone has a Delta L value of 25 or less, the pattern can remain; if it exceeds 25, a solid-color patch is required.
- Visibility: The rule aims to maintain clear visibility of player numbers for all stakeholders while allowing teams to keep their traditional patterns when contrast allows.
If you've been watching the UEFA Champions League this week, you might have spotted something curious about striped and half-and-half kits - while some teams can keep their design behind player numbers, others are forced to use solid-color spaces. Barcelona's Blaugrana half-and-half design continues behind their numbers, but Feyenoord must use a solid white patch on their green and white shirt. What's the story behind this seemingly inconsistent rule?
Big thanks to our follower Robin for asking us about this topic. Feel free to ask us any questions regarding kits via social media or our Contact Form.
"Kit Mystery": Why Some Striped Backs Are Forbidden in Football Kits
The answer lies in the official Equipment Regulations and a technical measurement called "Delta L" that determines whether stripes can remain visible behind player numbers.
The Delta L Kit Rule Explained:
• The contrast between colors in the Number Zone must have a Delta L value of 25 or less
• If the Delta L value exceeds 25, teams must use a solid-color patch behind the number
• Delta L is measured using a spectrophotometer to ensure objective assessment
What Does This Mean in Practice?
When two colors on a striped shirt are similar in tone (like Barcelona's blue and maroon), the Delta L value is low, and the pattern is allowed to continue behind the number. However, if the stripes contrast too much (like Feyenoord's green and white half-and-half design), teams must ensure a solid background patch to ensure number visibility.
The regulation aims to ensure player numbers are clearly visible for officials, players, media, and spectators, while still allowing teams to maintain their traditional striped designs when possible.
So next time you're watching a match and notice these differences in kit designs, you'll know it's not arbitrary - it's all down to the science of color contrast!
