How to use layer styles (bevel & emboss) on large sized print images

I have an image I am trying to create that effectively needs to look like a carved jade pendant. I have created a very successful version, but it has since been decided that we need to be able to print this image on large printed materials, such as posters etc - so the image needs to be able to print as large as about 30cm across. My image will not print anywhere near that large. So it's back to the 'drawing board'

I used the bevel and emboss layer styles to created the 3-dimensional raised look I required. However, when I work on my 'large image', the highest degree of bevelling etc I can create is still too narrow to produce the effect. I need around 4 to 5 times the size of bevel.

How can I achieve the same effect I get when using layer styles, on a significantly larger image?

(My image is based on a circle, with a spiral inversed from the outside, to the centre)

How about creating the image @1/2 or 1/4 print size. Make the bevel/emboss.

Then enlarge in a page/layout app.

Remember - you dont need high resolution for large format prints because the viewing distance is usually a great distance from the print.