If you see “Design 21” on the São Paulo birch wood art board and an edition number such as 07/25 on its reverse, you are looking at two separate identification systems. They describe different parts of the artwork’s identity and should both be retained in a collector’s record.
Design 21 identifies the São Paulo artwork within the Chromatica City Series. It is the design identifier shared by the São Paulo boards in this edition. The number on the reverse identifies one individual board within the limited worldwide edition of 25 pieces.
In short, Design 21 is the artwork number; 07/25 would be the individual edition number. Design 21 does not mean that the board is copy 21 of 25.
The Short Answer: Two Numbers with Different Roles
| Identifier | What it identifies | Does it vary between boards? |
|---|---|---|
| Design 21 | The São Paulo artwork within the Chromatica City Series | No. It remains the design identifier for this artwork. |
| 01/25–25/25 | An individual birch wood board within the limited 25-piece edition | Yes. Each board carries its own number on the reverse. |
This distinction matters because collectors often use the words design number, edition number and serial number interchangeably. On this product, “Design 21” and the reverse edition marking are not alternative ways of writing the same number. Combining them into one value would remove useful information.
A board marked 07/25, for example, should not be described simply as “number 21,” and it should not be catalogued as “21/25.” The complete identification would retain both facts: Design 21, edition 07/25.
What “Design 21” Identifies in the City Series
“21 São Paulo” is part of the first Chromatica City Series, a 25-design collector platform based around graffiti, train culture and urban creativity. Within that system, 21 is assigned to the São Paulo design.
That makes Design 21 a useful answer to the question: Which City Series artwork is this? It distinguishes the São Paulo artwork from the other designs in the series. It does not answer the separate question: Which physical board from the São Paulo edition do I own?
The design identifier therefore remains the same across the São Paulo boards in this edition. If one collector owns board 03/25 and another owns board 19/25, both collectors have Design 21. Their individual edition numbers differ, but the underlying City Series artwork is the same.
What Design 21 does not mean
- It does not mean that the board is the twenty-first copy in the wood edition.
- It does not replace the number written on the reverse.
- It does not describe the total size of the birch wood edition.
- It does not establish when the individual board was engraved, sold or dispatched.
- It should not be rewritten as 21/25 unless the reverse of that specific board is actually marked 21/25.
The cleanest term for it is design identifier or City Series design number. Calling it an edition number risks confusing the identity of the artwork with the identity of the individual physical piece.
What the Reverse Number 01/25–25/25 Identifies
The São Paulo birch wood edition is limited to 25 pieces worldwide. Each board is individually numbered on the reverse using a format that runs from 01/25 through 25/25.
This reverse marking answers the question: Which numbered piece within the 25-piece edition is this board? Unlike Design 21, it varies from one board to another.
The precise number of a particular board must be read from that board’s reverse. It should not be guessed from product photography, an order sequence, a purchase date or the “21” in the design name. Unless the reverse marking has been checked, the accurate description is simply individually numbered within an edition of 25.
That point is particularly important when giving the work as a gift, adding it to a collection database or preparing documentation after purchase. A product-level description can confirm the edition range, but only inspection of the physical board can confirm whether the individual example is 01/25, 07/25, 21/25 or another number in the edition.
How to Read an Edition Number Such as 07/25
An edition number is normally read as two connected values:
- 07 identifies the individual numbered board.
- 25 states the total number of pieces in this limited edition.
Accordingly, 07/25 can be read as “number 7 from an edition of 25.” The leading zero is part of the displayed numbering style, so it is sensible to preserve it in formal records when the board itself is marked that way.
The denominator is not the City Series design count in this context. Although the first City Series is also described as a 25-design platform, the “/25” on the reverse belongs to the numbering of this physical São Paulo birch wood edition. It tells you the edition size, not which city design you are viewing.
A useful test
When a number is unclear, ask what the number is identifying:
- If it identifies the São Paulo artwork in the City Series, it is Design 21.
- If it identifies the individual board within the limited edition, it is the reverse number, such as 07/25.
- If it states how many boards belong to the edition, it is the denominator 25 in the reverse notation.
These values can appear close together in a catalogue description, but they should remain separate data points.
Where to Find and Record Each Identifier
The individual edition number is placed on the reverse of the board. Check it directly before entering a specific number into a catalogue, insurance inventory, gift record or collection list.
Design 21 belongs to the product’s City Series identification. When documenting the piece, label that information explicitly rather than leaving an unexplained “21” in a general number field.
| Record field | Recommended entry |
|---|---|
| Artwork or design | São Paulo |
| Series | Chromatica City Series |
| Design identifier | Design 21 |
| Individual edition number | Enter the exact reverse marking, for example 07/25 |
| Edition size | 25 pieces worldwide |
| Format | A4 landscape, approximately 29.7 × 21 cm |
| Material | 3 mm birch wood |
| Artwork process | Permanent laser engraving |
| Certificate | Chromatica Certificate of Authenticity included |
If your cataloguing software offers only one field called “number,” do not force both identifiers into a single unexplained value. Use a note such as “City Series Design 21; board numbered 07/25 on reverse”. That wording preserves the distinction even in a simple spreadsheet or notes application.
A Simple Catalogue Entry for the São Paulo Board
A concise collector entry can read:
São Paulo Graffiti Train Birch Wood Art Board, Chromatica City Series, Design 21, edition 07/25, permanent laser engraving on 3 mm birch wood, A4 landscape, approximately 29.7 × 21 cm. Certificate of Authenticity included.
Replace 07/25 with the number actually found on your board. If the reverse has not yet been inspected, omit the example number and write:
Chromatica City Series, Design 21, individually numbered edition of 25; exact board number to be verified from the reverse.
This is more accurate than entering an assumed number and correcting it later. It also separates confirmed product information from information that depends on inspecting the individual piece.
For a collection spreadsheet
A practical spreadsheet can use separate columns for:
- Brand or artist
- Artwork title
- Series
- Design number
- Edition number
- Edition size
- Material
- Dimensions
- Certificate present
- Condition notes
- Photograph reference
Separate columns make future searches much easier. You can filter for all City Series works, find Design 21 specifically or sort individual edition records without treating every occurrence of “21” as the same kind of number.
How the Certificate of Authenticity Fits into the Record
Each São Paulo board is supplied with a Chromatica Certificate of Authenticity. The certificate is part of the collector documentation and should be stored carefully with the record for the artwork.
It does not remove the need to record the marking on the reverse. The certificate and the physical board are related documentation, but the reverse remains the direct place to verify the individual edition number assigned to that board.
Unless you have inspected the individual certificate, do not assume that it reproduces or matches a particular edition number. Record only what is visibly present. A careful documentation note might state:
- Board: reverse marked 07/25
- Certificate: present
- Certificate details: recorded separately after inspection
This approach avoids turning an assumption into a catalogue fact. It is especially helpful if the board and certificate are later stored separately, photographed for an archive or transferred together to another collector.
Should You Photograph Both Identifiers?
Yes. A useful visual record should show both the identity of the artwork and the individual numbering of the physical board.
At minimum, consider taking:
- A full view of the front showing the complete São Paulo artwork.
- A clear view of the reverse, including the individual edition number.
- A separate photograph of the Certificate of Authenticity.
- Additional close views of any distinguishing natural grain, surface texture or existing marks.
The full front image establishes which artwork is being documented. The reverse image confirms the individual edition marking. The certificate image records the accompanying document as it actually appears rather than relying on memory.
Keep the original image files if practical, and name them clearly. For example, a file name can include Design-21 and the verified reverse number as separate elements. Avoid naming a file “21-of-25” merely because the artwork is Design 21; that would incorrectly convert the design identifier into an edition number.
Photographs are also useful because birch is a natural material. Grain, base color and surface texture can vary from board to board, and the engraving may show subtle tonal differences. Those visual characteristics are separate from the formal numbering, but they can help document the particular physical object in your collection.
Common Numbering Mistakes to Avoid
1. Treating Design 21 as board 21/25
This is the central mistake. Design 21 identifies the São Paulo artwork within the City Series. Only a board actually marked 21/25 on the reverse should be catalogued as edition 21/25.
2. Dropping the denominator
Recording only “07” loses the edition context. The complete notation 07/25 shows both the individual number and the total edition size.
3. Recording an example number as the owned number
A number used in an explanation or product example is not proof of the number on your board. Inspect the reverse before making a specific entry.
4. Assuming numbering reveals production order
The reverse number identifies a place within the edition. Without production records, it should not be treated as evidence that one board was engraved before another.
5. Assuming numbering reveals sale or dispatch order
An edition number does not by itself show whether the board was the seventh piece sold, packed or dispatched. Those are separate events requiring separate records.
6. Assigning extra value to a particular number
The verified product information establishes a strict 25-piece edition, but it does not establish that lower numbers, matching numbers or any other particular positions carry greater rarity, collectibility or resale value.
7. Letting the certificate replace a board inspection
The Certificate of Authenticity belongs in the record, but the individual reverse marking should still be inspected and documented directly.
8. Using one number field for two meanings
An entry such as “21/07/25” is difficult to interpret and can look like a date or a single serial code. Use labels: Design 21; edition 07/25.
What the Numbers Do Not Establish
Design and edition numbers provide identification, but they should not be made to support conclusions beyond their documented role.
Neither number by itself establishes:
- The order in which the boards were manufactured or engraved
- The order in which they were sold or dispatched
- The purchase date or ownership history of a particular board
- The condition of the board
- A higher market value for one edition number over another
- That every board has identical grain, color, texture or engraved tone
- Affiliation with, licensing by or endorsement from a transport operator
The São Paulo artwork is an independent artistic interpretation of train culture. Its City Series identifier and limited-edition numbering document the Chromatica artwork and physical edition; they do not indicate an official relationship with a transport operator.
The Reliable Way to Describe the Board
For accurate documentation, keep the identification in two parts:
Design 21 = the São Paulo City Series artwork.
Reverse number = the individual board within the 25-piece birch wood edition.
If the board is marked 07/25, the correct combined description is “São Paulo, City Series Design 21, edition 07/25.” If you have not inspected the reverse, record the edition as limited to 25 and leave the individual number unconfirmed.
That small distinction produces a cleaner collection record, prevents the design number from being mistaken for a copy number and keeps the identity of the artwork separate from the identity of the individual board.
