Clackamas County tested ballots printed in-house, not from printer responsible for blurred barcodes
The county didn't test voting machines until May 3, and it tested ballots printed in-house — not from the printer that printed ballots going out to voters.
...
That is not the way it is done in Multnomah and Washington Counties. Each run actual ballots from the printer which supplies the ballots for voters. The test makes sure the vote counting machines are tabulating votes correctly and that the ballots are readable.
...
Multnomah County tested its vote counting machines with sample ballots from the printer on April 12 and 13, according to Scott. That would have given the county weeks to prepare if they discovered a problem. Scott said the ballots were counted perfectly by Multnomah County's machines.
https://www.kgw.com/article/news/local/clackamas-county-election-delay-ballot-test/283-8bfec541-fe40-4c63-b13f-d8a6e1897052
