Security Envelope Backgrounds

background-color: #fff;
background-image: 
  repeating-linear-gradient(45deg, #aaa 0, #aaa 1px, transparent 1px, transparent 6px),
  repeating-linear-gradient(-45deg, #aaa 0, #aaa 1px, transparent 1px, transparent 6px);
background-size: 12px 12px;

background-color: #fff;
background-image: 
  repeating-linear-gradient(135deg, #ccd 0 1px, transparent 1px 6px),
  repeating-linear-gradient(-135deg, #ccd 0 1px, transparent 1px 6px);
background-size: 10px 10px;

background-color: #fefefe;
background-image: 
  repeating-linear-gradient(90deg, #bbb 0 1px, transparent 1px 6px),
  repeating-linear-gradient(0deg, #bbb 0 1px, transparent 1px 6px);
background-size: 8px 8px;

background-color: #fff;
background-image: 
  repeating-linear-gradient(60deg, #6a8a7b 0, #6a8a7b 1px, transparent 1px, transparent 5px),
  repeating-linear-gradient(-60deg, #6a8a7b 0, #6a8a7b 1px, transparent 1px, transparent 5px);
background-size: 14px 14px;

background-color: #fff;
background-image:
  repeating-linear-gradient(45deg, #999 0, #999 1px, transparent 1px, transparent 4px),
  repeating-linear-gradient(-45deg, #999 0, #999 1px, transparent 1px, transparent 4px);
background-size: 8px 8px;

background-color: #fdfdfd;
background-image:
  repeating-linear-gradient(30deg, #bbb 0, #bbb 1px, transparent 1px, transparent 12px),
  repeating-linear-gradient(90deg, #bbb 0, #bbb 1px, transparent 1px, transparent 12px),
  repeating-linear-gradient(-30deg, #bbb 0, #bbb 1px, transparent 1px, transparent 12px);
background-size: 16px 16px;

background-color: #fafafa;
background-image:
  repeating-linear-gradient(45deg, #ccc 0, #ccc 1px, transparent 1px, transparent 10px),
  repeating-linear-gradient(-45deg, #ccc 0, #ccc 1px, transparent 1px, transparent 10px);
background-size: 14px 14px;
opacity: 0.8;

background-color: #fff;
background-image:
  linear-gradient(#aaa 1px, transparent 1px),
  linear-gradient(90deg, #aaa 1px, transparent 1px);
background-size: 6px 6px;

  background-color: #fff;
  background-image:
    repeating-linear-gradient(25deg, #5a6d85 0 2px, transparent 2px 10px),
    repeating-linear-gradient(60deg, #5a6d85 0 2px, transparent 2px 10px),
    repeating-linear-gradient(120deg, #5a6d85 0 2px, transparent 2px 10px),
    repeating-linear-gradient(150deg, #5a6d85 0 2px, transparent 2px 10px);
  background-size: 18px 18px;
  opacity: 0.9;

  background-color: #fff;
  background-image:
    radial-gradient(#8db2d3 0.8px, transparent 0.8px),
    radial-gradient(#8db2d3 0.8px, transparent 0.8px);
  background-size: 10px 10px;
  background-position: 0 0, 5px 5px;
  opacity: 0.9;