This mix works with the most common 3D printer builds and usually does not require too much attention in terms of finetuning the amount of dye and initiator.
Monomer: 1000 ml 1,6-Hexanediol diacrylate (Aldrich 246816)
Dye: 0,06 g Sudan I (Aldrich 103624)
Initiator: 20 g Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (Aldrich 511447)
1000 ml optically opaque HDPE bottle + funnel
OR 1000 ml optically opaque brown/amber glass bottle + funnel
OR new unused paint tin (make sure it has a coating on the inside)
Precision balance or measuring spoon
Dark room or Box
No food and no eating at the workplace. Photoinitiators contain heavy metals and are, as well as the other chemicals, toxic and may never get into your mouth. If you get some of it in your mouth, immediately (!!!) see a doctor.
Work in a cool, well ventilated and not too bright lit light protected environment
Make sure, that no unaware persons or children have access to your workplace, your chemicals or your equipment.
Make sure your workplace has no direct sunlight and is not to bright lit. Put the momoner into the stirrer and switch it on. Set the speed of the stirrer to a low level, just so that you don’t get a deep vortex (a vortex can result in air bubbles in the print, you probably don’t want that). Then add the dye, and let it mix until its quiet homogenous, it will completely solve later. The dye additionally protects the resin from the light, so it should be added before the photoinitiator. Then, add the photoinitiator to the running stirrer. Make sure the stirring pot is standing rock solid on the stirrer and will never slip of the stirrer due to vibrations of the stirrer motor. You will have to let the resin be stirred now for at least 3 full days at a light-protected place like a dark room or a box, until all the components have completely dissolved in the resin. If after three days, no solid leftover is visible in the pot, the photopolymer is ready to be used in your 3D printer. Otherwise, fill the resin (the funnel helps) into the light opaque bottle or coated tin can, where it can be stored for at least half a year.