>>9525338Lego's quality control issues really started around 2004-2006 when they changed up their molding techniques, plastic and just began to use Chinese manufacturers. This sacrifice in quality allowed the company to greatly expand their color catalogue, more affordably produce pieces and bring more detailed molds and prints into sets, which ultimately ended up saving the company.
Prior, all plastic for Lego pieces was in the form of pre-pigmented abs pellets. That's why vintage sets are almost entirely red, white, blue, yellow and black. Now, they mix pigments in-house into a translucent, milky colored abs. Pigments are impurities in the plastic and certain colors affect the curing process in the polymer chains, causing brittleness and other chemical reactions. Color consistency is also much more difficult as exact amounts of pigment, mixing time, environmental factors, etc all play a role in the final product.
Around this time, Lego was also expanding it's licensed themes and struggling with the costs of making new, highly detailed molds. Largely, pieces for themed character based mini figures. Lego was able to make deals through Chinese manufacturers to create some of these pieces for them. A lot of the specialty molds for themes like Toy Story, Star Wars, etc were made from a Chinese sublet. And while quality is comparable, it's easy to tell they aren't "normal" lego. The plastic is less shiny, it's lighter and there are injection indentations on the underside of pieces, like in the arms of mini-figures. This also lead Lego to being able to push out a large amount of new molds, prints and figures cheaply, which lead to the CMF line of mini-figures, which are largely made in China. in 2016 the Jiaxing factory in China was built, and although it mostly serves the Chinese market, many pieces are still produced for global sales.
