Epson C13S041342 A4 Matte Photo Paper 189gsm 50 sheets

Your printer will take a Compatible Paper Weight of up to 300 g/m², however I would consult the Epson manual or contact Epson to ensure that this paper is correct for that printer.https://www.epson.co.uk/support

This may be a bit heavy for this printer. Looking at the technical specifications for this printer, the suggested media for this printer is Matte Paper Heavy Weight, DIN A4, 167g/m2 - see this link for the paper recommended:
https://www.epson.co.uk/en_GB/products/ink-and-paper/paper-and-media/matte-paper-heavy-weight%2C-din-a4%2C-167g-m2%2C-50-sheets/p/729

Or see the link for the tech specs for this printer and choose media types

https://www.epson.co.uk/en_GB/products/printers/inkjet/consumer/ecotank-et-2850/p/30588

No, according the printer's specifications at https://www.epson.co.uk/en_GB/products/printers/inkjet/consumer/ecotank-et-8550/p/29217?cid=ps:google:gen23-gb:111::&aff_code=EUPSG100171&gclid=EAIaIQobChMIraztq8qQgQMVDdvtCh2FUQ7YEAAYASAAEgLw2fD_BwE&gclsrc=aw.ds the maximum paper weight for the EcoTank ET-8550 is 75gsm

Although your Canon PIXMA iX6850 A3+ Colour Inkjet Printer isn't listed as compatible on their website at https://www.epson.co.uk/en_GB/products/ink-and-paper/paper-and-media/archival-matte-paper---a4---50-sheets/p/749?pid=749#compatibility, it does state that this is compatible with inkjet printers, however it also states that only with pigment inks. For more information about the different inks available, please see https://www.cartridgepeople.com/support/solutions/articles/80001015112-dye-versus-pigment-inks