Gandolf50, what brand of acrylic lacquer?
I live in the States, the only brand I use is the in-house Walmart Brands, and as you might know, Wally-World will suddenly just stop carrying a brand for no reason, even when it is a best seller...
I really liked the store brand of Crystal-Klear and all the options set bellow.
Rustoleum 2x Ultra-Cover, Clear Satin-fast dry -non-yellowing -UV resistant Acrylic Laquer is a good choice when a cheaper brand can't be found...
honestly, as long as it is Acrylic Laquer UV-resist-Non-yellowing your good to go, and I usually try for the cheapest I can find, a 9$ can of spray paint is absurd!!! ~ yadda-yadda...~ and my Moto:
"I look for the cheapest way possible!"!
To use...Take your printed sheets OUTSIDEon a CLEAR-CALM day, as this stuff stinks and is toxic to the old' lungs. You won't be doing this in the middle of Winter!
Line up several sheets face-up, and spray each holding the can about 10" or so away, Spray R>L or L>R and then up and down, till it is covered with ( NO RUNS)! Go to NEXT.
Wait... Takes less than a minute for this to dry, so by the time you get to the 3rd sheet the first will be cold but dry!
Finish all the sheets...
Wait till dry to touch and any over-spray is dry also...Flip them over and do it again...
What your aiming at is for the sheet to turn translucent, which will ensure the Laquer has penetrated front to back... No worries..it will not be translucent when dry!!!
~And to ease fears... I have never had any printing ..RUN or anything...in fact, you will be sealing the printer ink under the Laquer.~
EDIT...If you use PHOTO-PAPER ( why would you?) to print your models...I HAVE NO IDEA what effect this may have on them! I would not suggest this until you made a test run!!!!!