In the late 1960s Ribeiro, in yet another direction, began a new series of paintings. These were hard-edged geometrical abstractions, with repeated enamel-like shapes deliberately placed to create a harmonious pattern. Utilising his oil and PVA mixes, multiple planes appear to ascend off a flat ground, as in the Yantric Shift series.
He explained these works would not have existed were it not for the ‘evolving form of Tantra’ (traditional practice/ritual from Hinduism/Buddhism) which:
“...has led the conscious mind through stages to a point of total acquiescence and negation of the Self… directed at the two senses, sight and sound. Yantras (visual; diagrammatic, involving form and colour). Mantras (sound; repetitive, tonal and syllabic).”
He had secured much-needed exposure in the US with these paintings which were sent for exhibition in solo shows at the Deson-Zaks Gallery, Chicago (1970), and the Triangle Gallery, San Francisco (1971). However, en-route, “all of the work got stuck at a Greyhound Warehouse in Salt Lake City... while they tried to locate where they were”. With the near two-week delay, the Chicago show was off.
Problems of his unclaimed and unsold ‘Chicago paintings’ would continue to plague him. A long-standing friend, Jack Goldfarb, appealed to the gallery 30 years later to trace the work but hit a brick wall, commenting:
“I felt how could people be so cold-blooded about an artist's work, something someone had spent so much time and effort on... it came to a dead end and he lost those paintings.”