We produce brilliant full color posters as wide as 60" by any length. Popular posters sizes are;
What is the correct resolution that will yield the best results for my poster?
If you are building your poster artwork to be printed at 100% (building your page to 18"x 24" to print to 18" x 24" size) then the correct resolution is 72 ppi. However, if you are building your poster artwork to be enlarged (building your page to 18" x 24" to be printed to 36" x 48" size), then we recommend a resolution at twice the ppi, or roughly 150 ppi. When in doubt always use graphics that are larger than the minimum required as we can down sample without losing image quality.
Is RGB or CMYK the better color space to use?
There is a lot of confusion regarding which color space to use when designing for print. It is understandable because we view artwork on an RGB monitor, yet print posters on a CMYK device. Generally we get pretty good results from either color space. Since RGB is a larger color space than CMYK it is generally considered a best practice to work in RGB and have the conversion to CMYK take place at the printer.