Ruby Requires Chilkat v11.7.0+

A PDF Watermark That Only Appears When Printed

See more PDF Watermark Examples

Demonstrates a watermark that is invisible on screen and appears on paper, which is what a "printed copies are uncontrolled" marking needs. Two approaches can do it: an optional-content layer with layer.view off and layer.print on, which also gives the reader an entry in the layers panel of the viewer (layer.locked stops them switching it), and a Watermark annotation with annotation.view false and annotation.print true. annotation.fixedPrint keeps the printed size and position the same whatever paper it goes on. Ruby

require 'chilkat'

success = false

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  The PDF used in this example is available at two_page_memo.pdf

pdf = Chilkat::CkPdf.new()
success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

json = Chilkat::CkJsonObject.new()
json.UpdateString("type","text")
json.UpdateString("text","UNCONTROLLED WHEN PRINTED")
json.UpdateString("id","printonly")

#  As a layer: off on screen, on when printing, and locked so the reader cannot switch it on.
json.UpdateString("approach","layer")
json.UpdateString("layer.name","Print marking")
json.UpdateString("layer.view","off")
json.UpdateString("layer.print","on")
json.UpdateBool("layer.locked",true)

json.UpdateString("rotation","diagonal")
json.UpdateString("scale.fit","page")
json.UpdateNumber("scale.fitPercent","70")
json.UpdateNumber("opacity","0.3")

jsonOut = Chilkat::CkJsonObject.new()
success = pdf.Watermark("add",json,jsonOut)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "layer id: " + jsonOut.stringOf("id") + " pages: " + jsonOut.stringOf("pages") + "\n";

success = pdf.WriteFile("qa_output/memo_print_only.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

#  The same thing as an annotation instead.
pdf2 = Chilkat::CkPdf.new()
success = pdf2.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

json2 = Chilkat::CkJsonObject.new()
json2.UpdateString("type","text")
json2.UpdateString("text","UNCONTROLLED WHEN PRINTED")
json2.UpdateString("id","printonly2")
json2.UpdateString("approach","annotation")
json2.UpdateBool("annotation.view",false)
json2.UpdateBool("annotation.print",true)
json2.UpdateBool("annotation.fixedPrint",true)
json2.UpdateString("rotation","diagonal")
success = pdf2.Watermark("add",json2,jsonOut)
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

print "annotation id: " + jsonOut.stringOf("id") + "\n";

#  Sample output:

#  layer id: printonly pages: 1-2
#  annotation id: printonly2