SMP-MODPACK/.minecraft/config/modelfix-client.json

{
  "default": {
    "item_quads_expansion": 0.0,
    "item_quads_indent": 1.0E-4
  },
  "mac_os": {
    "item_quads_expansion": 0.0,
    "item_quads_indent": 0.0099,
    "shrink_ratio_multiplier": 1.0
  }
}