Thats it really missus just had her frame back from Argos (quality work chaps !)and wants to keep it looking good .Probably gonna do the whole length of underside of downtube so gonna need a fair bit !

Got mine from BikeTart, has gone very yellow after 2 years. I guess that’s okay????? Would have preferred it if it stayed clear.

Tape!

I’ve found the stuff from Just Riding Along is excellent for the money, it seems to be more adhesive than others I’ve tried. A little bit thicker and robust than other brands, but goes on fine with a bit of heat.
HTH

The stuff from Helitape is far too thick IMO. Takes a lot of heating to get it to fit and stick. Days after its been applied, it will move very easily if the frame is clamped, not great.

I’ve found that the stuff from 3M is the best.

http://www.evanscycles.com/products/extra-uk/bike-shield-full-pack-ec005431

whilst it is expensive, it doesn’t yellow over time,it’s easier to apply than any other type i’ve tried and is thick enough to provide good lasting protection.