Discovered by Zas and kurocat471 on May 16th, 2023.
MSD is currently the fastest and easiest way to dupe materials. To perform this glitch you have to be mid-air, either in a shield jump, gliding, or on the Mineru Construct.
There is no risk of losing items when you are only duping one unique material at once. If you dupe multiple different materials and you mess up the inputs you could lose materials. Y and + can be pressed in the same frame or Y can be pressed one frame after +.
Discovered by Li Shen (鯉神) on May 15, 2023.
DUD is the current one of the slowest method of material duplication and the first to be found. It is not recommended over other methods, but is still usable and risk-free.
How to perform DUD
To perform DUD you need to have at least 2 bows, 1 arrow, and a material you wish to duplicate. Laggier spots such as Lookout Landing or Water Temple works best for this trick, as may Zora's Domain.
A good cue for this glitch working is that the fused item still appears to be attached to the bow in the pause menu, and that Link in-game also has the item still fused to the bow. Another cue is that when both bows drop, they are on top of one another however this is not 100% certain. As also mentioned, this is the slowest and objectively hardest version of material duping and we would strongly recommend MSD to be optimal or MIT to be the safest.
Discovered by eXe on May 20th, 2023.
MIT is the second-fastest but safest method of item duplication. It works in a very similar way to MSD, but uses an additional item that isn't duplicated. It also needs to be done during a shield jump, while gliding or in the Mineru construct.
The item you want to have duplicated must be in the last invenotry slot or some items may be transmuted. This can be stacked with multiple sets of single items to dupe a large amount, as the singular item in the dupe, if picked up afterwards, will become the last inventory slot. Depending on the area, the maximum items out at any one time before they begin despawning is around 20, so keep that in mind when trying to get lots of a particular item.