Fluorescein, 0.03 mol dissolved in 80 mL H2O and 0.06 mol KOH, condensed with 0.06 mol HCOH, AcH, furfuryl and salicyl aldehydes, each 10 h at 100degreesC, H2O distilled off, gave greenly fluorescing red polycondensates, which redissolved in H2O, precipitated with 0.1 M HCl, filtered, washed with H2O, and dried, yielded red, yellow-orange, brown, and orange dyes m. (infusible), 294-6, 300-5, and 326-9degreesC in 78.8, 71.1, 75, and 70.4% yields, resp. The dyes were sot. in alcohols, Me2CO, HCONMe2, insol. in H2O and toluene; salts were sot. in H2O. IR spectra confirmed the structures. The fluorescein-HCOH dye was brominated (91.8% yield; 2 Br atoms/mer) to give a deeper-red infusible dye, sol. in EtOH and HCONMe2. Rhodamine B polycondensed with HCOH gave a dark-rose dye, m. 163-5degreesC, sot. in Me2CO, alcohols, H2O, and CH3Cl. Luminescence spectra (excited lambda=330 nm) of the fluorescein-HCOH dye (340-470 nm; max. 400 nm) and its Na salt (430-570 nm; max. 435 and 520 nm) are given. The dyes can dye acrylics, paints and varnishes. 21 refs.