When selecting a resin from a different manufacturer than the 3D printer, it is important to consider its compatibility. The compatibility of a resin is established on the basis of two parameters: the wavelength for which it has been optimised and the technology for which it has been formulated.
Compatibility according to the wavelength of the light source
3D printing resins use photoinitiators to trigger polymerisation by light. There are different types of photoinitiators optimised for different wavelengths, so there must be compatibility between the photoinitiator (and therefore the resin) and the printer's light source.
Image 1: Visible light spectrum. Source: Wikipedia.
Resins optimised for three wavelengths are available on the market: 365 nm, 385 nm and 405 nm, with 405 nm or those compatible with all three wavelengths being the most common. Therefore, special attention should be paid when choosing resin if you have a printer with a 365 nm or 385 nm light source. This does not mean that it is not possible to use a resin optimised for a wavelength other than that of the printer, but its performance will be much lower and will require much longer exposure times.
It is always advisable to select a resin that is optimised for the wavelength of the printer to be used, in order to achieve the best results with the shortest exposure time.
Similarly, it should be taken into account when selecting a curing equipment that includes lamps with the appropriate wavelength.
Compatibility according to technology
In general, there are two groups of resins depending on the compatible technology: SLA and LED/DLP. It is not recommended to use resins developed for LED/DLP in SLA printers and vice versa, as they tend to have different reactivity. Although some resins may work well in other technologies, this cannot be guaranteed and in some cases will be impossible.
Image 2: SLA vs DLP vs MSLA. Source: theorthocosmos.
Incompatibility of resins is not a common problem because formulations compatible only with 365 nm and 385 nm or optimised for SLA are currently in the minority.
