As I mentioned in another thread, I have an Epson L351 Multi-function printer. It cannot print to the top, or the left edge of the page.
What I is a blue block at the top of the A4 page, 210mm wide. The bottom of this block is a nice curve.

I tried to set the page 6mm from the correct position in my printer, and set the page size to custom, 6mm wider and longer than A4, but I cannot get it to print to the left edge. The print job fails. I suppose there is an LED and it does not see any paper, so it does not print.

It can print to the right edge, because the printer can take paper wider than A4, up to 230mm.

I found a print shop to print the top blue block on my paper. Does anyone know a trick to print to the top and the left, edges short of buying an A3 printer?

Hi.

On the printing material side you cannot hack the printer to print from edge to edge.
It is a regular solution to print an image exceeding the final edges of a paper on a larger sheet, and crop the print after.
There is a render printing marks extension in inkscape that may come handy drawing the cropmarks.

I suggest trying to print on a 230 mm wide paper.
http://www.novaoffset.com/Nova/What_are_Bleeds_and_Crop_Marks.html

Hi.

Although most "modern" printers these days can print border-less the Epson L351 does not fall into that category.
Border-less printing is not supported on the Epson L350 series printers.