Illinois began registering cars and bicycles in 1907. Owners were required to purchase a dashboard disc from the state and supply their own license plates. These plates were made from about anything. Leather, wood, sheet metal,etc. In 1909 kits were available that consisted of a plate with slots. The numbers attached to the plates with tabs through the slots. In 1910 a plate was manufactured that some old timers consider the real first issue, not 1911. The plates were issued half way through 1910. In 1911 the state started issuing yearly plates, because people abused the system by just making up plates and not registering their cars. Prior to 1907 Chicago issued brass license plates, 1904 - 1906. These plates are extremely rare. Bicycles were registered because they were considered a nuisance. The dashboard discs do say bicycle  on them and are sometimes confused with motorcycle tags. From 1907 to 1910 there are no dates on the discs. Adding to the abuse of the system. Later plates had ventilation holes or slots for radiator mounting. The 1913 plate had it's numbers cut out for this purpose. The size of earlier plates depended on how many numbers were on it. 1927 Illinois had the shape of the state with the date and Land of Lincoln first appeared in 1954. Reflectorized plates began in 1966. From 1943- 1948 soybean cardboard plates were issued to conserve metal during the war. Not all of the different types of plates were soybean. Motorcycle plates during that period were metal. Prestate plates are often faked and care should be taken when buying them. The kit plates with inserted letters are the most reliable. I knew a guy 30 years ago who made 1913 front plates and aged them to look old. He sold quite a few until he got caught. Know what you're buying!!! Hope this helps some. For the most part Illinois plates have been pretty boring. Care and restoration of plates. Obviously buy plates in the best condition possible. Keep in mind though, plates from the teens,20's or older are hard to find in mint condition, if not impossible. A few years ago I missed out on two pairs of 1912 Ill plates that were unused. The women sold them for 5$ each. So it's not impossible, but rare. Older plates should have as much of the original paint as possible. Extra holes are not uncommon, because of the need to attach them to all the different types of vehicles. I generally don't use anything stronger than water or very mild detergent to clean plates. Do not use Oxy clean unless you want to remove all the paint. Learned my lesson on an old California plate. Stripped it clean. Just remove surface dirt. Don't scrub and remove paint. If in doubt leave it alone. You would be surprised what is considered acceptable on really old plates. Restoration is an option only if it is done well and not necessarily to increase the value of the plate. On an average plate you can only expect to get about 50% of what the plate would worth in mint condition. At a cost of about 40 to 50 dollars to restore it better be worth it. I've only had a couple done, but for display purposes. Make sure the plate is solid, with no heavy rust or pitting. If it is going to take more than paint stripper to prep the plate for repainting it may not be worth it. Ask the person for examples of his work and whether the colors can be matched very closely. If the colors are too far off it will reduce the value of the plate. Also make sure the back of the plate is painted properly as well. Please keep in mind that even a plate with only some of the original paint, is more desirable than one that has been repainted. Many serious collectors won't consider buying a plate that has been restored unless it's extremely rare or dirt cheap. Any questions, don't hesitate. I am by know means an expert but I have been collecting for over thirty years. Good hunting. Gregg