Coming soon · the family tree of the work

The artist signs the certificate. The object wears the bind.

Stemma binds an identity-checked artist, a signed certificate, and a tamper-evident tag on the work itself. One record a collector can trust, a gallery can hand over, and an insurer can file.

First 100 artists onboard for free. No spam, one launch email.

Harvest, ii

Bekezela Mabena · 2024 · oil on canvas

Threshing floor I

Bekezela Mabena · 2023 · oil on canvas

Study for a dry season

Bekezela Mabena · 2025 · charcoal on paper

What we are building

Four layers. No shortcuts between them.

01

Person

Each artist verifies their identity before issuing certificates. Their public artist name is backed by that check.

02

Claim

The artist signs the certificate with the work’s title, year, medium, dimensions, and official images. Any correction becomes a dated update.

03

Object

A tamper-evident tag links the physical work to its certificate. The work itself is checked too, so a copied tag alone is not enough.

04

Registry

A blockchain record anchors proof of the certificate and custody history. The timeline can be public without exposing private owners.

Who it is for

Each route fits the work.

For artists

  • Verify once, issue for life
  • Sign each certificate yourself
  • Custody tracked to the day

For galleries

  • Take work on loan with proof
  • Every handover dated and documented
  • Overdue returns carry evidence

For collectors

  • One record you can verify
  • Collection value as real events
  • An insurance file insurers accept

A certificate is only as strong as the hand that signed it, and the object it is bound to.

Stemma keeps the three apart: who signed, what the record says, and what is in your hands. Each one checkable on its own.

The verify moment

Tap the tag. Four checks. One answer.

A collector holds the phone to the back of the work. Stemma checks the artist, certificate, physical work, and shared custody history, then shows a clear result: verified, failed, tampered, or unable to read.

  • Artist identity confirmed
  • Certificate remains authentic
  • Physical work matches the record
  • Custody history, where shared
9:41

Verified

Harvest, ii

Bekezela Mabena · identity verified · 12 Mar 2026

STEM-08F3A1