prawn：Prawn::Table::Cell :border_style

#!/usr/bin/env ruby

require "prawn"
require "prawn/layout"

pdf = Prawn::Document.new

y = 700
[:all, :no_top, :no_bottom, :sides, :none, :bottom_only].each do |bs|
  Prawn::Table::Cell.new(
    :document => pdf,
    :point    => [100, y],
    :text     => "#{bs}",
    :border_style => bs).draw
  y -= 50
end

pdf.render_file(File.basename($0, ".rb") + ".pdf")