In this tutorial, I show you how to export cards for printing with Make Playing Cards (MPC). I'm by no means a printing expert, but here's the process I'd use for poker cards:
Note: the video says 3mm of bleed but it actually should be 3.052mm for pixel perfect export.
Apply 3.052mm of bleed to your Poker cards in the dextrous export page. (This number will give you pngs at exactly 1122 x 822 px)
Export your pngs at 300dpi
Choose Traditional poker size cards (2.5 x 3.5 inches) in Make Playing Cards. and choose your paper type etc. The important thing is making sure whatever card type you choose in MPC matches whatever you've made in Dex.
Load in your exported pngs to Make Playing Cards (if you get a 'low resolution' warning, you've probably forgotten to apply bleed in step 1).
Check your settings are correct and process your order :)
Note: the cards in the video above have already been optimised with bleed in mind, so you'll need to do that first. Checkout the section on Bleed.