pre-embedding (especially useful for small endoscopy biopsy specimens) for histopathology processing to make salt bridges and gel plugs for use in electrochemistry. in formicariums as a transparent substitute for sand and a source of nutrition. as a natural ingredient in forming modeling clay for young children to play with. as an allowed biofertilizer component in organic farming. as a substrate for precipitin reactions in immunology. at different times as a substitute for gelatin in photographic emulsions, arrowroot in preparing silver paper and as a substitute for fish glue in resist etching. as an mri elastic gel phantom to mimic tissue mechanical properties in magnetic resonance elastography gelidium agar is used primarily for bacteriological plates. gracilaria agar is used mainly in food applications. in 2016, amam, a japanese company, developed a prototype for agar-based commercial packaging system called agar plasticity, intended as a replacement for oil-based plastic packaging.