I have a D1 Pro 20w. I've searched the community and can't find any suitable settings to be able to engrave on jute burlap/hessian. I've tried my own test grid on a sample of the material but either nothing shows up or I get a lot of ‘melting’ of the fibres. I really need help please with power/speed/no. of lines and whether to have air assist on or not. Thanks in advance for any help you can give me