On Tue, 13 Jul 2021, Jeong Dal wrote:

> Dear Aditya,
> 
> Thank you for your code and an explanation.
> 
> > Let's assume that the last MPpage was a \startuseMPgraphic{boxes} .... \stopuseMPgraphic. Suppose I wanted to use these pictures in a presentation. On the first slide, I can use
> > 
> >    \useMPgraphic[stacking=0]{boxes}
> > 
> > to show the three boxes, and on the next slide, I can use
> > 
> >    \useMPgraphic[stacking={-1,0}]{boxes}
> > 
> 
> I tried to reproduce your example using \startuseMPgraphic{boxes} … \stopuseMPgraphic, and useMPgraphic[stacking=0]{boxes} .
> A modified one of your code is below.
> There is no error message but no output at all.
> Would you please tell me what is wrong in here?

> [...]
> \startuseMPgraphic[offset=2mm]{boxes}
> [...]

You cannot use [offset=2mm] here. Just use \startuseMPgraphic{boxes}.

Aditya