You already know the answer 😀

You should use an image editing software, such as GIMP (Windows and Linux) or Paint .NET (Windows only) to resize the image as you'd like. However, most of the printing shops should do that for you, but if you want to make sure, better to do ir yourself. I have also framed some A3 printings, however I used high resolution scans of game covers, so you might want to reconsider using such low resolutions images for printing A3s (unless you're going for the pixelated look on purpose, of course)

GabrielKnight123 wrote:

games default to 4:3 ratio no matter what custom resolution I put in the config file

I think this is down to settings in your video card driver's control panel. If you have an nvidia card, go to the section labelled "Adjust Desktop Size And Position" and change the scaling settings there.

Resizing as bregolin suggested is probably the easiest way though. But if you're a bit like me, maybe you don't like it when your PC doesn't obey you 🤣

Resizing it would be better in my opinion. However, if you don't know what you are doing I would just ask the print shop to do it for you (as long as it is a proper print shop and not just some copy place).

If you want crisp pixels, I would ask the shop to resize it using "nearest neighbor" algorithm to something around 300dpi before stretching the pixels to A3 ratio.

EDIT: Also, those 46 pixels are onluy 2.4% of the screen. Maybe a better option would be to keep pixels square and just add tiny bars on the side using a dominant color? I think it might be barely noticeable.

Also, if you don't have that many screens to do, feel free to send them my way and I can set them up for printing for you. Just let me know if your printer requires CMYK color scheme.

Thanks everyone from what you were saying I will try to keep it without stretching to fill the A3 so it will look as close to the original as possible I will just make the borders black as the frames are black too, the choice I have to make now in the dosbox config is between using opengl which is a bit blurry but looks like it would on a CRT and openglnb which looks pixelated like on a modern LCD in an emulator I will do a test to get a print of both opengl/openglnb and since these will be on a wall at a distance I probably wont notice if they are pixelated and sharp looking compared to a bit blurry.