module Prawn::SoftMask

The Prawn::SoftMask module is used to create arbitrary transparency in document. Using a soft mask allows creating more visually rich documents.

You must group soft mask and graphics it’s applied to under save_graphics_state because soft mask is a part of graphic state in PDF.

Example:

pdf.save_graphics_state do
  pdf.soft_mask do
    pdf.fill_color "444444"
    pdf.fill_polygon [0, 40], [60, 10], [120, 40], [60, 68]
  end
  pdf.fill_color '000000'
  pdf.fill_rectangle [0, 50], 120, 68
end