Attach packing slip print with Item fulfillment email

 var packingslip = render.packingSlip({
                        entityId: parseInt(recordId),
                        printMode: render.PrintMode.PDF,

                    });

 email.send({
                                author: 2228,
                                recipients: custEmail,
                                cc: ccArray,
                                subject: subject,
                                attachments: [packingslip],
                                relatedRecords: {
                                    transactionId: createdFrom
                                },
                                body: body
                            });