There are two paper types that you could pick for your poster and are as follows:
1) Epson Enhanced Matte Paper is ideal for anyone looking for a flat matte surface. This paper is perfect for images that do not require gloss. It yields highly saturated images, while maintaining excellent highlight and shadow detail.
2) Epson Ultra Premium Luster Photo Paper is in between a gloss and matte finish, providing you with highly saturated, maximum ink coverage.
Perfect for framing.