VB.NET 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. VB.NET

Dim success As Boolean = 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

Dim pdf As New Chilkat.Pdf
success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If


Dim json As New Chilkat.JsonObject
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")

Dim jsonOut As New Chilkat.JsonObject
success = pdf.Watermark("add",json,jsonOut)
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If

Debug.WriteLine("layer id: " & jsonOut.StringOf("id") & " pages: " & jsonOut.StringOf("pages"))

success = pdf.WriteFile("qa_output/memo_print_only.pdf")
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If


'  The same thing as an annotation instead.
Dim pdf2 As New Chilkat.Pdf
success = pdf2.LoadFile("qa_data/pdf/two_page_memo.pdf")
If (success = False) Then
    Debug.WriteLine(pdf2.LastErrorText)
    Exit Sub
End If

Dim json2 As New Chilkat.JsonObject
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) Then
    Debug.WriteLine(pdf2.LastErrorText)
    Exit Sub
End If

Debug.WriteLine("annotation id: " & jsonOut.StringOf("id"))

'  Sample output:

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