Understanding Set Types

Learn how to classify and work with different types of trading card sets, including the distinction between parallel sets and variation sets.

What are Set Types?

Trading card sets come in many forms beyond the standard base set. Understanding the different set types helps you accurately categorize and manage your card data. The Trading Card API provides boolean flags and relationships to help you distinguish between these types.

Set Type Overview

Base Sets

The primary set of cards in a product release. Base sets contain the core cards that define the product.

Characteristics:

• Main checklist of the product
• Usually the largest set in a product
• Other sets reference the base set as their parent

Example: The 350-card base set in 2025 Topps Allen & Ginter

Parallel Sets

Complete reproductions of a base set with a different visual treatment. Parallels include every card from the base set.

Characteristics:

• Same card numbers as the base set
• Same number of cards as the base set
• Different card stock, finish, or numbering (e.g., Gold /50, Refractor)
• is_parallel: true in the API

Example: 2025 Topps Chrome Refractor parallel - all 350 base cards available as Refractors

Variation Sets

Partial reproductions of a base set with a different visual treatment. Variations include only a subset of the base cards.

Characteristics:

• Same card numbers as the base set (but fewer cards)
• Different visual treatment or design
• Typically more limited in scope
• is_variation: true in the API

Examples:

• 2025 Topps Allen & Ginter "Tin Type Variations" - Only 99 of 350 cards available in vintage tin-type style
• 2025 Topps Allen & Ginter "Chrome Variations" - Only 99 cards available with chrome/refractor finish

Insert Sets

Special themed cards inserted into packs, separate from the base set.

Characteristics:

• Different card numbering than base set (usually prefixed, e.g., "INS-1")
• Themed content (e.g., "League Leaders", "Rookie Stars")
• Variable rarity across the insert set

Autograph Sets

Cards featuring authentic player signatures.

Characteristics:

• May be standalone or parallel versions of other sets
• Usually serial numbered
• Higher value and collectibility

Relic Sets

Cards containing pieces of game-used memorabilia (jerseys, bats, etc.).

Characteristics:

• Physical memorabilia embedded in the card
• May be standalone or combined with autographs
• Usually serial numbered

Parallel vs Variation: Key Differences

Aspect	Parallel (is_parallel: true)	Variation (is_variation: true)
Card Count	Same as base set	Subset of base set
Card Numbers	All base card numbers	Only some base card numbers
Completeness	Complete parallel of base	Partial variation of base
Example	Gold /50 (all 350 cards)	Tin Type (99 of 350 cards)

When to Use Each

Use is_parallel: true when:

• The set includes every card from the base set
• Collectors can build a complete parallel set
• The only difference is the card treatment/numbering

Use is_variation: true when:

• The set includes only some cards from the base set
• The variation applies to a limited selection of players/cards
• Collectors cannot complete a full parallel

API Examples

Creating a Variation Set

POST /v1/sets

{
  "data": {
    "type": "sets",
    "attributes": {
      "name": "Tin Type Variations",
      "is_variation": true,
      "total_cards": 99
    },
    "relationships": {
      "parent": {
        "data": { "type": "sets", "id": "<base-set-uuid>" }
      },
      "product": {
        "data": { "type": "products", "id": "<product-uuid>" }
      }
    }
  }
}

Creating a Parallel Set

POST /v1/sets

{
  "data": {
    "type": "sets",
    "attributes": {
      "name": "Gold /50",
      "is_parallel": true,
      "total_cards": 350
    },
    "relationships": {
      "parent": {
        "data": { "type": "sets", "id": "<base-set-uuid>" }
      },
      "product": {
        "data": { "type": "products", "id": "<product-uuid>" }
      }
    }
  }
}

Response with Set Type Fields

{
  "data": {
    "type": "sets",
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "attributes": {
      "name": "Tin Type Variations",
      "description": "Vintage-style tin type treatment of select base cards",
      "card_count": 99,
      "is_variation": true,
      "is_parallel": false,
      "created_at": "2025-01-15T10:30:00Z",
      "updated_at": "2025-01-15T10:30:00Z"
    },
    "relationships": {
      "parent": {
        "data": { "type": "sets", "id": "base-set-uuid" }
      }
    }
  }
}

Filtering by Set Type

# Get all variation sets
GET /v1/sets?filter[is_variation]=true

# Get all parallel sets
GET /v1/sets?filter[is_parallel]=true

# Get all base sets (neither parallel nor variation)
GET /v1/sets?filter[is_parallel]=false&filter[is_variation]=false

Real-World Example: 2025 Topps Allen & Ginter

Here's how a complete product might be structured:

Set Name	Type	is_parallel	is_variation	card_count
Base Set	Base	false	false	350
Gold Border /50	Parallel	true	false	350
Mini	Parallel	true	false	350
Tin Type Variations	Variation	false	true	99
Chrome Variations	Variation	false	true	99
World's Champions	Insert	false	false	50

Best Practices

1. Use Parent Relationships

Always link parallels and variations to their parent base set:

"relationships": {
  "parent": {
    "data": { "type": "sets", "id": "<base-set-uuid>" }
  }
}

This enables:

• Navigating from variations to base cards
• Understanding set hierarchy
• Calculating collection completion

2. Be Accurate with Card Counts

Set total_cards accurately:

• For parallels: Should match the base set count
• For variations: Should reflect the actual subset count

3. Document Visual Differences

Use the description field to explain what makes this set different:

{
  "description": "Vintage tin-type photographic treatment on thick cardstock"
}

4. Consider Both Flags

A set can have neither flag (base set, insert), one flag (parallel or variation), but typically not both. If a set reproduces all cards with a treatment, it's a parallel. If it reproduces only some cards, it's a variation.

Common Misconceptions

"Short Print Variations"

Short print variations within a base set (where some base cards have rare photo variations) are different from variation sets. SP variations are typically tracked at the card level, not the set level.

"All Non-Base Sets are Parallels"

Insert sets are neither parallels nor variations - they have their own independent numbering and content.

Next Steps

• Data Models - Complete Set model reference
• API Reference - Sets endpoint documentation
• Data Provenance - Track where your set data comes from
• Building Card Tracker - Build an app using set data