I do something different which is exporting the created pdf into png files which takes a heavy toll on the main thread. Do you know if there is a way to compute the below? if (!isPdf) { int pageIndex = 1 ; await for ( var page in Printing.raster(pdf.save(), dpi: 300 )) { final image = await page.toPng(); final String pageQty = (pagesToPrint > 1 ) ? ' $pageIndex - $pagesToPrint ' : '1-1' ; file = File( " ${output.path} / $fileName -- $pageQty .png" ); await file.writeAsBytes(image); imageList.add(file); pageIndex++; } } else { file = File( " ${output.path} / $fileName .pdf" ); await file.writeAsBytes(pdf.save()); imageList.add(file); }