I found these two wooden divided boxes at Goodwill for $1.99 each. They are perfect for our cutting strips and envelope sealing work.
The widest divider holds envelopes and a little tray to collect the pieces after cutting.
The three-year-olds love this work and the tray that lets them take all of the work to the table at once might add to its appeal. It would be ideal if the scissors could be in the center to avoid encouraging left-handedness. Let's watch and see if that turns out to be a true obstacle or one I have imagined.