Unfortunately my clients are only interested in fine art paper... an opinion I agree with... so I'll have to live with it.
Or do they just think of matte papers as being the only "Fine Art" papers? :-]
Do you know if Print Shield or Moab's Desert Varnish Spray would help? I've used Print Shield and it does nothing to hide scuffs once they're there.
Print Shield and Desert Varnish are the same solvent based product. None of the aresol can products are going to do much for changing the surface.
I'm assuming your reference to a liquid laminate refers to the aforementioned sprays... but will look at the links you kindly supplied to see if there is something else in liquid laminates that I'm unaware of.
Water based products like PremierArt's Eco-print shield, ClearStar Type C and Lumina's AquaCryl are three excellent options. They are available ina variety of surfaces (satin, semigloss, gloss, etc). These modern water based products don't come in an aresol can and require brushing, rolling or spraying via an HVLP system (preferred). They will change the surface, durability and look of your prints. Some people love it, others don't care for it on matte papers.
That's hard road making prints that size on matte paper. Lots of throw aways, redos, frustration, shipping problems, etc. And it's not going to change - it's the nature of the game. I understand your frustration. I've been exhibiting digital prints on matte surface papers since 1991 and am so glad we have the options that we have today. Matte papers aren't the only fine art papers out there. I'd encourage you to consider other paper and coating options with an open mind.