🚀 go-pugleaf

Apologies if this is a FAQ....This regards Plain TeX, not LaTex....

I often prepare documents which include a number of "\topinserts" on various
pages, so that I can later paste figures into the blank areas appearing on the
final output.

It would be _fantastic_ if I could specify all the these "\topinserts"
(and other insertions, such as in the middle of the page) at the beginning of
my document; for example, the following would be great:
	\top{10 cm}{1}      %for 10cm insertion on page 1
	\top{5 cm}{6}     %for 5 cm insertion on page 6
	(etc. etc.)

I know too little about TeX, unfortunately, to be able to readily construct a
macro to do this.  However, I do know TeX gives the user control over
what appears on various pages (e.g., \ifnum\pageno=...), and also on how
the final document is put together.  So I am cautiously optmistic that such a
macro could be written.

Might anyone know of a way to accomplish this task?

Many thanks!