why is the background black when with Chartjs export to a image

Question

I have a problem when i try to export the chart to an image. The backgound is black and this is the code:

var canvas=ctx;
var canvasImg = canvas.toDataURL("image/png", 1.0);

//creates PDF from img
var doc = new jsPDF('landscape');
doc.setFontSize(20);
doc.text(15, 15, "Cool Chart");
doc.addImage(canvasImg, 'JPEG', 10, 10, 280, 150 );
doc.save('canvas.pdf');

Answer 1

This is a bit more complicated than simply what image format is being used. You need to explicitly set the canvas background to white. But exactly when to do this can be tricky. Please see my answer in a similar question.