In todays market, I have seen alot of reproductions (fake) Nippon pieces. Some are very well done, and painted beautifully, and others are very obvious as they are not the quality of the true Nippon pieces.
These pieces are getting into the United States from China. They use a phony mark (there are several!) on the bottom of the piece, and to get it into the US, all they need to do is put a paper label on it stating that it was made in China. Once in the US, the paper label is easily removed, and the piece is passed off as a true aged, antique!
When you purchase a real Nippon piece, you are purchasing porcelain that was made before 1921 (all pieces after 1921 were marked Japan or Made in Japan). This porcelain has true value, whereas the fake pieces will never gain the value, no matter how pretty they are. These fake pieces are being seen in hatpin holders, powder jars, vases etc. On the vases, I have noticed that the real Nippon is glazed on the inside of the vase. The fake pieces are not.
There are 3 fake wreath marks. One with the "M' in the middle is missing the stem on the leaf. One has an upside down "K" in the middle of the wreath, and another with an hourglass in the upside down wreath. There are two rising sun marks; one from Japan that has zigzagged rays, and one from China that has fewer rays than the true Nippon mark, and the sun is not a solid color. On the real mark, the sun is all colored in. There is also a fake RC mark that is all in green, whereas the real mark has the words Hand Painted in red.
In order to keep from having problems when you are selling Nippon, Limoges or RS Prussia pieces, be sure to learn the differences in the marks and also in the look and feel of the pieces. Invest in a jewelers loup so that you can take a very close look at the marks. True Nippon collectors will be very upset if they purchase a piece from you, and find after receiving it, that it is not a true Nippon piece, but a cheap reproduction.
There are many good reference books out there, plus websites that have the marks for you to compare. Take the time to do this before listing these pieces.