[StuBeeDoo]

Most of down this neck of the woods use Patto's no custom though.
https://www.pattosplace.com/home.html

Thanks.  
I've used Patto's in the past, and would again.  This time I'm specifically after getting sheets I've drawn printed.

[Scuderia_Turini]

Hello Stuart I am on my second colour laser so that I can print my own. First one was a Samsung CLP something and it lasted about 5 years until I scratched the drum thing when cleaning.  I ignored the warnings about not using "special papers" and never had a problem. I think it might have been different if was using it continuously and the heat built up but doing a couple of sheets in quick succession was ok. I am now using a Brother HL-L3230CDW and only difficulties have been tuning the colours to give good density on large areas and that the manual feed for the decal sheets sometimes needs a hand (that may be due to the sheets I am using now).
With laser technology there is no need to apply any sealing spray, the decals are ready to use. 
Unfortunately the affordable colour lasers cannot print white so some innovation is required.

In 2017 I used decal sheet to do a "wrap" on the Rover below. There were a few bits that I had to fill in with paint but a more skilled designer could have created a better set of decals. 

Leo

   

[ZeGas]

OK Leo now my ears have pricked up, don't want to hijack this thread, so I'll start another regarding printers.
I've been printing my own on my cheap inkjet but the ink is very thin.