#### Set style fill transparent

Some terminals support the attribute transparent for filled areas. In the case of transparent solid fill areas, the density parameter is interpreted as an alpha value; that is, density 0 is fully transparent, density 1 is fully opaque. In the case of transparent pattern fill, the background of the pattern is either fully transparent or fully opaque.

Terminal | solid | pattern | pm3d
gif | no | yes | no
jpeg | yes | no | yes
pdf | yes | yes | yes
png | TrueColor | index | yes
post | no | yes | no
svg | yes | no | yes
win | yes | yes | yes
wxt | yes | yes | yes
x11 | no | yes | no

Note that there may be additional limitations on the creation or viewing of graphs containing transparent fill areas. For example, the png terminal can only use transparent fill if the `"`truecolor`"` option is set. Some pdf viewers may not correctly display the fill areas even if they are correctly described in the pdf file. Ghostscript/gv does not correctly display pattern-fill areas even though actual PostScript printers generally have no problem.