<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg viewBox="0 0 820 320" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <desc>Example mask01 - blue text masked with gradient against red background
  </desc>
  <defs>
    <linearGradient id="Gradient" gradientUnits="userSpaceOnUse"
                    x1="0" y1="0" x2="800" y2="0">
      <stop offset="0" stop-color="white" stop-opacity="1" /> <!-- this end is filled -->
      <stop offset="1" stop-color="black" stop-opacity="1" />
    </linearGradient>
  </defs>
  <mask id="Mask" maskUnits="userSpaceOnUse"
     x="0" y="0" width="800" height="300">
     <rect x="0" y="0" width="800" height="300" fill="url(#Gradient)"  />
  </mask>
  <rect x="0" y="0" width="800" height="300" fill="#FF8080" />
  <rect x="0" y="100" width="800" height="100" fill="blue" mask="url(#Mask)"  />
</svg>