Paper

Agoria Scale Models
Offers a movie theater model.
http://www.agoria.com/model.html

Cardstock
Offers automobile, ships, civil, WWI and WWII aircraft.
http://www.teuton.org/dbarnett/

Conception Editions ARC
Offers 3D model collection of buildings of Montreal, Canada.
http://www.copticarchitecture.com/a.htm

Daisey Designs
Provides race cars, racing airplanes and Chevy Corvairs sold as PDF downloads.
http://www.daisey-designs.com

Fiddlersgreen
Sells paper models of airplanes, buildings, and other items. Many free models to download.
http://www.fiddlersgreen.net/

Geoblox
Sells patterns that demonstrate geology concepts.
http://www.geoblox.com/

Gryf Hobby
Distributor of World War II vehicles and aircrafts and architectural models. Poland.
http://www.gryfhobby.com/index_e.htm

Heritage Models
Architectural card models of notable buildings in and around London, including the much acclaimed model kit of Shakespeare's Globe Theatre.
http://home.clara.net/rogerpattenden/

Hobby Factory
Offers a wide variety of models such as trains, military vehicles, ships, aircraft, and accessories.
http://www.hobbyfactory.com/

IDA 3D
Offers kits from flat sheets to form replicas of buildings from around the world.
http://www.ida3d.com

Impact Models
Designs and markets architectural card such as Victorian houses, town centre shops, town hall, and banks. Mail order.
http://impactmodels.co.uk/

Micromodels USA
Offers historical boats and architectural model.
http://www.micromodelsusa.com/

Origami Papercraft
Offers airplanes, buses, trains.
http://www.origamipapercraft.com

The Paper Airplane Company
Sells 1/40th scale paper model airplanes.
http://www.thepaperairplanecompany.com

Paper Creations
Scale and non-scale paper models. Printed on ordinary printer paper, these kits don't look like paper when they are done.
http://www.papercreate.com

Paper Landmarks
Pre-cut 3D world landmarks including the Eiffel Tower, Chrysler Building, Chicago skyscrapers, Leaning Tower of Pisa. Order by pieces or theme sets worldwide.
http://www.paperlandmarks.com/

Paper Model Store
Offers Polish and East European card models, with an assortment of military ship and airplane models.
http://www.papermodelstore.com

PROTOTYP
Specialist in 1:24 paper model racing cars. The subjects are thoroughly researched and the models are extensively detailed.
http://prototyp.org/

Scale Paper International
Offers a variety of architectural, aircrafts, military vehicles and kids models, and magazine.
http://www.e-papermodels.com/

Vita Paper Models
Offers a variety of aviation, transportation, ships, and architectural models.
http://www.purpleline.com/vita/vitamain.htm