I used the Polymark dimensional fabric and craft paint pen on the white lines on the knobs. It dries fairly quick and easily peels off. It's not a pen. It's more of a small tube with a small nipple on the top. It's made by Duncan Enterprises and I found a picture:SickCelica696 said:What did you do to the knobs? I just sprayed over everything, then scratched off the white part. Paint came off instantly on the white part and didn't damage it at allvindiCAtor said:I did however use the fabric paint pen on the knobs and wow those turned out perfect. So unfortunately I didn't find out about the Polymark fabric paint pen until after I painted the HVAC panel.