90D best file type to convert to for photos of fine art to send to print on demand services

[EdCanonEOS90D]

What should I convert my raw pics on the 90D into for best fine art print on demand services?
For example, I have a picture which the original jpeg (which was taken by the camera automatically at the same time as the raw image) had a file size of under 11 MB (this was less than 1/3 the size of the raw file which was about 38MB). I bought this camera because it can take higher quality pics, and 11 MB is not so high any more for professional quality pictures. FYI, I must be able to print large versions of prints made from photos of fine art.

I created a second file which is a new jpeg using DPP4, which is an Exif-JPEG - this JPG is about 21MB – is this actually a higher quality image than the first JPED - what is the actual resolution - is it is higher quality? The file size is twice as big so I hope the quality is much higher.

I created a third file using DPP4 which is a TIF file (I think more software can handle TIF files than raw CR3 files, and TIF has been around a long time and is pretty standard), and this file is a ExifTIFF 8bit TIF. This is very large at 94MB. Is this actually a higher quality image than the first JPEG or second JPEG file - what is the actual resolution - is it is higher quality?

I created a fourth file using DPP4 which is another kind of TIF file, and this is a TIFF 16bit TIF – it is very large at 189MB. Can you see this one and tell if it is higher quality? Is this actually a higher quality image than the first JPEG or second JPEG file or third TIF file - what is the actual resolution - is it is higher quality?

Which kind of file should I convert the raw file to for best resolution for print on demand service for fine art, i.e., photos taken by the 90D of original fine art which will be used for prints of various sizes (we want to sell the largest print size possible). The services I have seen do not take raw but will take JPEG or TIFF. I want to convert and save to one type and store these files in the cloud. As you can see from above, 32MB can become 189MB but it this the best choice? Thanks, Ed   [Email address removed for privacy]

[rs-eos]

The resolution may be the same between RAW and JPEG.  It all depends upon your settings.  So first ensure you have the JPEG images set to capture the highest resolution.  That will then match the resolution of your RAW captures.

Second, please note that you can categorize images into two basic camps in terms of compression: lossy and lossless.  JPEG is lossy.  Decreasing the quality of a JPEG will decrease its file size.   TIFF I believe is mostly lossless; thus leading to larger file sizes.   Also, TIFF can capture more than 8-bits per pixel whereas with JPEG, you just get 8-bits per pixel.

For the best possible quality, capture in RAW. You'll want to then look up whether or not you want to work in sRGB or Adobe RBG color spaces.  Edit your images as needed, then output for print.