but on Printful I go out of the print area under the bottom line, there would be all over printing but it costs too much.
Only on polyester shirts as well.
Alternatives to Pritful?
My problem is print vertical graphics (9_16 format) on the whole front side
I have personal experience on the issue, and it is an issue even when you have your own printer.
The problem is that a 52cm (full back print) on size S and M tees will have to be 58cm on the L and XL sizes, or they will look odd.
When doing baggy/oversized tees the problem gets even worse and a print up to 70cm may be needed.
Most small printers (Epson F2100, Brother GTX and similar) can print only up to around 50cm length.
This is one of the reasons I have custom build Epson P800 conversions, capable of printing up to 80cm length.
That exceeds the size capacity of most DTG's. Kornits can go that big but most POD companies don't use them. Try to find someone with a Kornit.
I think Prinful use Kornit machines so they are capable of doing this, but for some reason they don't.
Probably they don't want to keep swapping platens for a small number of orders.
The additional cost of ink may be a reason for it as well.