Today I discovered the mkisofs command, a general linux command not specific to Ubuntu. This command enables you to make an ISO disk image of any folder or group of files on your hard drive or external media. I used it today to make an ISO file of a CD which appears to have worked perfectly using the following command
mkisofs -o EPSON.iso /media/cdrom0
The -o parameter specifies the desired output file-name (in this case EPSON.iso). This command has literally hundreds of paramaters which are explained better than I would even attempt here.