With dated third-party evidence: client engagement letters, contracts, invoices and self-employment tax records that together show at least three years of professional design work. A résumé and a portfolio illustrate the work but do not prove its duration.
Let the clients and the tax filings speak for the timeline
The experience limb of the Graphic Designer rule is satisfied by evidence, not assertion. Start with the largest clients and ask each for a short letter stating when the designer worked for them and what she produced; a lodge operator or an equipment brand that has used her for several seasons can confirm years at a time. Add signed contracts and a sample of invoices that show dates, deliverables and design fees.
Self-employment income schedules from tax returns tie the whole period together and are hard to dispute. Arrange the material in a table with one row per client, covering start date, end date and service, and let the reviewing officer or adjudicator total the months. If a gap exists, show it honestly rather than stretching a client relationship to cover it.
Keep the DEC transcript and diploma at the front of the package, because the experience evidence only matters once the diploma is established.