You can never complete a blueprint. Instead it should add all slab types to its normal cubic block since you can't have those blocks in your inventory otherwise, unless you use admin commands.
Instead of:
Blocks | Amount |
Green hazard armor | 5 |
Green hazard armor 3/4 | 10 |
Green hazard armor 1/2 | 5 |
It should be:
Blocks | Amount |
Green hazard armor | 20 |