Card Holder (Thiết Kế Kinh Dị)

Pros: 

• Easy to print, you can fit 2x on prusa mini, under 8h 
• Solid - 10% infill worked best for me, 5% was too low and it started to break a bit

Cons: 

• Hard to stack one on another, some helpers might be useful (I added quick joiners)
• Requires support

Improvement ideas: 

• You could print with no supports by turning the model onto the back, joining the upper card holder segments and adding supportive bracket to hold the raiser for bottom cards