C++ 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. C++

#include <CkPdf.h>
#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    bool 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

    CkPdf pdf;
    success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    CkJsonObject json;
    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");

    CkJsonObject jsonOut;
    success = pdf.Watermark("add",json,jsonOut);
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "layer id: " << jsonOut.stringOf("id") << " pages: " << jsonOut.stringOf("pages") << "\r\n";

    success = pdf.WriteFile("qa_output/memo_print_only.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    //  The same thing as an annotation instead.
    CkPdf pdf2;
    success = pdf2.LoadFile("qa_data/pdf/two_page_memo.pdf");
    if (success == false) {
        std::cout << pdf2.lastErrorText() << "\r\n";
        return;
    }

    CkJsonObject json2;
    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) {
        std::cout << pdf2.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "annotation id: " << jsonOut.stringOf("id") << "\r\n";

    //  Sample output:

    //  layer id: printonly pages: 1-2
    //  annotation id: printonly2
    }