Fill transparency of custom SVG symbol

Question

I'm trying to create a custom symbol using inkscape and editing the svg file to be able to manage it from the style window in QGIS.

Edited the .svg symbol file deleting the "style" lines and inserting the line (after "path" and "circle"):

fill="param(fill) #FFF" stroke="param(outline) #000" stroke-width="param(outline-width) 1"

I can edit lines colors/thicknesses and the fill color but I do not know how to edit file to get a transparent fill of the symbol. How can i fix it?

Answer 1

In the meantime, after reading SVG symbol colors differences in QGIS 2.12?, I solved the problem by editing the line:

fill="param(fill) #FFF" stroke="param(outline) # 000" stroke-width="param(outline-width) 1"

Adding fill-opacity="param(fill-opacity) 0" i.e.

fill="param(fill) #FFF" fill-opacity="param(fill-opacity) 0" stroke="param(outline) # 000" stroke-width="param(outline-width) 1"

changing the value of the parameter param(fill-opacity) between 0 and 1 it is possible to adjust fill opacity.