I tried single coasters taping a single image to individual coasters - too time consuming
I tried jig pressing 6 coasters at a time using a template and mdf jig from mdp - great but so much room for error I found I wasted far more coasters than I would have liked.
It looks like the mdf jig has warped a little after a few uses which even with a high pressure meant that one of the coasters would always turn out blotchy.
Lining up the printed template with the jig was easy enough but with one serious flaw, if the image was not perfectly aligned when it passed through the printer (skewed slightly) then all 6 coasters are heading for the bin.
I found sometimes the printer would print closer to one end shifting the whole template a cm down the sheet or up. This left all 6 images out of place too.
I now have returned to the single coaster method.
Printing my own coaster template using 95x95mm rounded squares x6 with a black stroke to mark the edges.
when printed I cut the sheet into 6 and tape individually.
It’s a shame there isn’t a clear jig where you can see the alignment to the sheet and flip over and press.