My experience with using Decal Paper & Printer for custom decaling is not very good with color. The only time the color shows up halfway decent is if it is applied on a very light object white being the best and even then the color is washed out. I think this has to do more with the Printer than the paper. I have not seen if a Laser Printer does color any better. There is white Decal paper that I have but not tried yet that may show color a little better but the problem with white is that cutting out your graphic will leave the white background so if you are applying to anything but a white background you have to be precise with your cutout. I have even tried clear address Label stickers stock (Avery) with the same washed out color results. Nigels are you using a different method or paper as I sure would like to know as creating only Black graphics on custom waterslide decals is so limiting. I also notice there are a lot of Ebay sellers selling copied Decal sheets but when you use them you get the same color washed out look. The decals look great on the paper backing until you use them. I know this as when I was looking for McDonald Decals I bought one of these. Best to stick with name brand Decals makers like MicroScale for authentic, beautiful Decals. Oops...I am rambling.
I've not actually tried making them yet Super, but I did quite a bit of research before buying as I wasn't sure what I needed to get. The general concensus is the white decal paper is better, but as you say you need to be very precise cutting them out.
I got mine with the intention of making that PlaRail Advance Nankai Rapi:t Star Wars train, I've got the paper, the sealer, the images, all I don't seem to find is the time to do it lol!
When I do I'll let you know how it goes!!
Happily collecting things all my life...
You Know Your Keeping It Real When Your Working With Steel!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Think when that new, official, Plarail non-motorized Ashima comes out, anyone will try and customize it to better look like the engine herself? I like these customs a great deal, but I have to wonder how they'll compare...