Paul Ysart (PY) came from a family of glassmakers. The Ysarts helped develop the highly successful Monart glass line at John C. Moncrieff Ltd. in Perth, Scotland.By the 1930s, Paul was producing millefiori paperweights in his spare time while working at Moncrieff. Paul's father and brothers also made paperweights, but Paul's work developed a character of its own. He continually refined his techniques, producing weights that collectors still recognize for their precision and craftsmanship.

Paul later produced paperweights under his own name and under the Harland brand (H cane). Peter Holmes and Willie Manson both worked alongside Paul before establishing notable careers of their own. Through his work and the generations of makers influenced by the Ysart family, Paul's impact on Scottish paperweight making remains difficult to overstate.