Nine Inch Cube
A cube of that size holds a stack of standard envelopes with room for the oversized cards that never fit anything, and it does not take over the table. The slot measures 5.9 by 0.2 inches, wide enough for a card with a bit of thickness to it, narrow enough that nothing falls back out when the box is carried to the car.
Folds Up in Minutes
The box arrives pre-folded flat, which keeps the panels from being crushed and makes assembly a matter of opening it out and tucking the tabs. Assembly takes a minute and one person can do it while the food is being set out. Flat storage also means it can be brought back out, refolded, and used again for the next occasion. Nothing about it needs a second pair of hands.
Maroon and Gold
Two colors that turn up on more school crests than most, which is why the box tends to match the gown in the photographs taken beside it. Printed with classic graduation elements on heavy paper, it reads as a centerpiece rather than a container, and it holds its shape through an evening of guests dropping envelopes into it. A ribbon or a framed photo propped against one side finishes the display.
Cash and Gift Cards
What goes in is rarely just paper. Gift cards, folded bills and checks all end up in the same box, which is an argument for a lid that stays on and a slot that does not gape. Opening happens after the guests leave, usually with a parent writing down names for thank-you notes as each envelope comes out. The box then goes on a shelf until the cards are answered.