The border-image-slice CSS property divides the image specified by border-image-source into regions. These regions form the components of an element's border image.
|Applies to||all elements, except internal table elements when border-collapse is collapse. It also applies to ::first-letter.|
border-image-slice: 20 fill;
Represents an edge offset in pixels for raster images and coordinates for vector images. For vector images, the number is relative to the element's size, not the size of the source image, so percentages are generally preferable in these cases.
Represents an edge offset as a percentage of the source image's size: the width of the image for horizontal offsets, the height for vertical offsets.
Preserves the middle image region and displays it like a background image, but stacked above the actual background. Its width and height are sized to match the top and left image regions, respectively.