For many years Gooch and Housego have been supplying very high laser induced damage threshold coated parts to projects such as the National Ignition Facility. We have optimised our substrate preparation and coating processes to achieve repeatable performance well in excess of 10Jcm-2, 1064nm 3ns pulses. This has used electron beam deposition technology. While this has performed well in the controlled environments of the science labs, it is well known that the coatings produced are porous and therefore susceptible to absorbing water and other chemicals from the atmosphere, modifying the coating performance. The traditional solution has been to select ion beam sputtering deposition techniques, but these are typically expensive, with smaller capacity chambers and produce high stress coatings. Therefore they are not optimal for higher volume components and thin substrates. We present the results of our development to optimise an ion-assisted deposition technique offering the possibility of trading off various design parameters including coating porosity and laser damage threshold, to optimise the coating performance of optics located where they can suffer contamination and outgassing. The coatings can be deposited in a large chamber at reasonable speeds suited to higher volume throughputs. Such coatings include the challenging design of a dual band visible and 1064nm optimised for both visible transmission range and LIDT performance at 1064nm.