It is not really an issue for the printer as it can print on anything flat. The issue comes up as to whether the ink will go on to the garment without bleeding and remain in it after being washed (if whatever you are printing on will be washed). Traditionally, dtg inks are made to adhere to natural fabrics. With the use of a specialty type of pretreat fluid, there have been success stories of printing on to synthetic fabrics. I do know someone that was able to print on a polyester / spandex blend where the spandex was around 35% of the fabric content and held up through the wash test. I have been told that spandex is an open cell type synthetic molecule that allows the dtg inks a chance to cure to them with the help of the pretreat fluid. However, other synthetic fabrics like nylon are a closed cell molecule and don't do as well. No clue how lycra will work.
It is important to note that the tests above are done just with CMYK inks - not white inks. So that needs to be taken into account well. Ultimately, it has nothing to do with the printer and everything to do with the inks being used.
Hope this answers your question as best as possible. Testing would be required.
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