This is a custom .yml file with custom backpacks for use with Smoothbrain's backpacks mod. It will not function without it.

MANDATORY: For this mod to work you must go to your Smoothbrain-Backpacks config settings and turn on "Use external YAML".

If there is any difficulty with the mod loading for you, simply rename the .yml contained to "Backpacks.yml" and add it to your configs folder. You MUST do the above step and check "Use external YAML".

Thanks to JamesJonesTV's mod I was able to figure out the exact format required for custom bags to work correctly.

This mod includes 4 new backpacks designed to accompany your progression through the swamp, mountains, plains and mistlands biomes.
The backpacks have their maximum properties available without upgrading, as I currently see Smoothbrain's backpack upgrades do not work. That being said, there are 10 coin optional upgrades so you can have the bag's star level match the tier of the bag. (2-3-4-5)
My bag balance intends for the starting default smoothbrain backpack to have 50% weight reduction or less with the default 5x3 (15) slots.
Keep in mind smoothbrain's mod has a setting to have the backpacks invisible on your character if you wish. ("Hide Backpack")

[ Adventurer's Backpack ]

Second Tier backpack for Adventurers who have braved the swamps. Weight of contained items reduced by 60%. Size: 6x3

Requires: Forge
  Iron: 30
  ElderBark: 60
  Guck: 30

[ Mountaineer's Backpack ]

Third Tier backpack for Mountaineers who have conquered the mountains. Weight of contained items reduced by 70%. Size: 5x4

Requires: Forge
  Silver: 30
  WolfPelt: 30
  JuteRed: 10

[ Pathfinder's Backpack ]

Fourth Tier backpack for Pathfinders who have crossed the plains. Weight of contained items reduced by 75%. Size: 6x4

Requires: Forge
  BlackMetal: 30
  LinenThread: 60
  LoxPelt: 10

[ Viking's Backpack ]

Fifth Tier backpack for true Vikings who have ventured to the mistlands and returned stronger. Weight of contained items reduced by 80%. Size: 7x4

Requires: Black Forge
  ScaleHide: 20
  Carapace: 20
  Eitr: 40
  JuteBlue: 8

Recommend using AzuExtendedPlayerInventory for a dedicated backpack slot: https://thunderstore.io/c/valheim/p/Azumatt/AzuExtendedPlayerInventory/

If you want to reclaim some (or all) of the resources used on bags you don't need anymore check out: https://thunderstore.io/c/valheim/p/Azumatt/Recycle_N_Reclaim/

For those who come after and may wonder why their custom bags had issues loading as I did; the order of backpack entries matters for several settings, and backpacks must contain an upgrade even if you don't care about using upgrades on them. Blank entries for backpack parts does not mean they are hidden. (Use visible/hidden/hexcode) Also, in the mod config it is mentioned 8 slots wide won't work, despite it working in other mods it doesn't work here from my attempt.

"Adventurer's Backpack":
  description: "Second Tier backpack for Adventurers who have braved the swamps. Weight of contained items reduced by 60%."
  size: 6x3
  unique: global
  appearance:
    BackpackBody: 555555
    BackpackFlap: 1f643e
    Sleepbag: 555555
    BackpackStrapTop: 1f643e
    BackpackStrapBottom: 1f643e
    Pot: hidden
    Teapot: hidden
    Knife: aaccaa
    Knifesheath: aaccaa
    Pickaxe: aaccaa
    MetalclipLeft: hidden
    MetalclipFrontLeft: 667166
    MetalclipFrontRight: 667166
    ToolstrapTop: 667166
    ToolstrapBottom: 667166
    RingBottomLeft: 667166
    PouchFront: 1f643e
    PouchLeft: 1f643e
  crafting:
    station: Forge
    level: 2
    costs:
      Iron: 30
      ElderBark: 60
      Guck: 30
  upgrade:
    1:
      Coins: 10
      size: 6x3
  weight factor: 0.40
  teleport: true

MANDATORY: For this mod to work you must go to your Smoothbrain-Backpacks config settings and turn on "Use external YAML".

Thanks to JamesJonesTV's mod I was able to figure out the exact format required for custom bags to work correctly.

This mod includes 4 new backpacks designed to accompany your progression through the swamp, mountains, plains and mistlands biomes.

The backpacks have their maximum properties available without upgrading, as I currently see Smoothbrain's backpack upgrades do not work. That being said, there are 10 coin optional upgrades so you can have the bag's star level match the tier of the bag. (2-3-4-5)

My bag balance intends for the starting default smoothbrain backpack to have 50% weight reduction or less with the default 5x3 (15) slots.

Keep in mind smoothbrain's mod has a setting to have the backpacks invisible on your character if you wish. ("Hide Backpack")

[ Viking's Backpack ]

Fifth Tier backpack for true Vikings who have ventured to the mistlands and returned stronger. Weight of contained items reduced by 80%. Size: 7x4

Requires: Black Forge ScaleHide: 20 Carapace: 20 Eitr: 40 JuteBlue: 8

If you want to reclaim some (or all) of the resources used on bags you don't need anymore check out: https://thunderstore.io/c/valheim/p/Azumatt/Recycle_N_Reclaim/

"Adventurer's Backpack": description: "Second Tier backpack for Adventurers who have braved the swamps. Weight of contained items reduced by 60%." size: 6x3 unique: global appearance: BackpackBody: 555555 BackpackFlap: 1f643e Sleepbag: 555555 BackpackStrapTop: 1f643e BackpackStrapBottom: 1f643e Pot: hidden Teapot: hidden Knife: aaccaa Knifesheath: aaccaa Pickaxe: aaccaa MetalclipLeft: hidden MetalclipFrontLeft: 667166 MetalclipFrontRight: 667166 ToolstrapTop: 667166 ToolstrapBottom: 667166 RingBottomLeft: 667166 PouchFront: 1f643e PouchLeft: 1f643e crafting: station: Forge level: 2 costs: Iron: 30 ElderBark: 60 Guck: 30 upgrade: 1: Coins: 10 size: 6x3 weight factor: 0.40 teleport: true