What are Terraria's mysterious negative-ID items?

Описание: What were Terraria's negative-ID items?
negative ID npcs? well, items too, apparently!
discord:   / discord  

Credits:
0:00 A intro-recap of something you may know... NPC IDs
0:52 What about negative item IDs?
1:15 In-game behavior
1:40 What were they used for?
1:58 Tool sprites... and tool variants
2:48 Weapon variants... peak Phasesaber!
3:09 Yet more recolored tools galore
3:33 The death of the recolored tool variants
4:21 A small "bugfix" on the Phasesabers
5:09 Conclusion & outro

Credits:
Good. Bad. I'm the Guy with the YoYo: The Terraria 1.3 Official Trailer by Re-Logic & Yrimir
   • Good. Bad. I'm the Guy with the YoYo: The ...  
Poradnik Terraria 1.2 - Tin, Lead, Tungsten, Platinum (Cyna, Ołów, Wolfram, Platyna) by Dodo
   • Poradnik Terraria 1.2 - Tin, Lead, Tungste...  
Terraria 1.1 Trailer by Re-Logic
   • Terraria 1.1 Trailer  
Let's Play Terraria Pt. 1 "Hello World" by Re-Logic
   • Let's Play Terraria Pt. 1 "Hello World"  
Let's Play Terraria Pt. 5 "Suicide is always the way home." by Re-Logic
   • Let's Play Terraria Pt. 5 "Suicide is alwa...  

Music:
Terraria - Underground
Terraria - Hallow

Mods and Packs:
Foundry & Alchemy (Pack) - https://steamcommunity.com/sharedfile...
Fancy Lighting [Ultra Preset] (Mod) - https://steamcommunity.com/sharedfile...
Stanberry Font (Pack) -
https://steamcommunity.com/sharedfile...
Stormdark UI (Pack) -
https://steamcommunity.com/sharedfile...
DragonLens (Cheat Mod) -
https://steamcommunity.com/sharedfile...
Better Zoom (QoL) -
https://steamcommunity.com/sharedfile...
Character Stats (QoL) -
https://steamcommunity.com/sharedfile...

What were Terraria's negative-ID items?