I made a business card for a family friend on Photoshop, went all gold, they got their business cards printed but now they want a sign made with the logo I made for them. So it needs to be blown up to a large scale but they can't use the psd file I made because it comes out too blurry. The printer can only us ai files. I opened the psd file in illustrator then saved it as a eps as requested by the printer, but when he opened it and zoomed in it was still blurt. How can I make this work?
As @Scott says, some sign places cut vinyl and want sheer vectors:
.dwg, some even take
.svg - so it depends upon your specific printer’s pipeline and production technology what file format and graphic methods they need.
Clearly a small-format pixel-painted business card design element will need to be redrawn as vector art prior to any use such as larger-scale signage or vinyl cutting; even if they can print from raster files, designing in vector and then exporting to a raster file in the size needed is the best practice anyway, and allows easy vector export as well as vari-sized raster exports.
You need to redraw as vector art from the get-go.
Hope this helps.