The mask-type CSS property sets whether an SVG <mask> element is used as a luminance or an alpha mask. It applies to the <mask> element itself.
/* Keyword values */ mask-type: luminance; mask-type: alpha; /* Global values */ mask-type: inherit; mask-type: initial; mask-type: revert; mask-type: revert-layer; mask-type: unset;
This property may be overridden by the mask-mode property, which has the same effect but applies to the element where the mask is used. Alpha masks will generally be faster to render.