Hello,
You should start with a position "0 : 0" and font size 14.
The current values seems to be very big for the PDF ; and PDF lib is not exactly working in pixels.
Regarding the font, "arial" is a system one. So if you have an error with that font it means that you're hosting do not have it available.
Courrier, Helvetica and Times are include in the HIkaSerial package.
You can also see to use the TCPDF font import system to add your own fonts in the HikaSerial media folder.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.