Thanks, Mark, for those tips.
Infact i've just realised i did not express myself correctly.
What really happens is this.

After prining, the paper is advanced some spaces to enable a tear off
which is desirable.
Now for the subsequent print it starts from where the printer head is located currenly, that is some paper is already lost due to the previous advance for tear off.

My real wish is for the paper to be reversed to save the large space on top.
Is this possible or is by design?

TIA