—Information accurate as of: build 904.83
The item that you use will be consumed if you successfully manage to make Blueprints of it. If unsuccessful you will lose the items used without durability (like ammunition), but items with durability will simply be completely worn down and can later be repaired. The amount of resources you need to craft the item from the blueprints are the same as the item would cost if you gained the required level and spent the xp to unlock it and make it that way, but when you craft an item with that blueprint it will have almost half durability that gets less when you repair it.
Because you gain several blueprints when doing this, it is very useful for low level players if they find a valuable weapons , tools or ammunition . If they fear that they will lose a valuable item when they are out in the world; it can be reassuring to know they can simply make another one of the item with the blueprints they have made.
Making blueprints using a 12 Gauge Slug with 3 Research Papers (For 100% success chance) at a Research Table resulted in 32 12 Gauge Slug Blueprints that costs 20 Metal Fragments and 20 Gun Powder each to make, but the original 12 Gauge Slug was consumed. So before reaching level 23 (the requiered level for this ammo) you can now make 32 12 Gauge Slugs at the cost of 1.