TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The etching paste comprises etchant chosen from ammonium hydrogen difluoride, ammonium fluoride, fluoroboric acid, sulfuric acid, nitric acid, iron(III) nitrate, iron(III) chloride, phosphoric acid, triethylammonium chloride, diammonium hydrogen phosphate, potassium bromate, potassium chlorate, potassium perchlorate, copper(II) chloride, potassium permanganate, potassium chromate, hydrochloric acid, ammonium hydroxide, hydrogen peroxide, potassium nitrate, potassium phosphate, and/or iron(II) sulfate. The etching paste comprises organic and/or inorganic particles in an amount of 0.5-20 wt.%. The inorganic particles are chosen from calcium fluoride, boron oxide, carbon black, graphite, fumed silica and sodium chloride as filler and thickener, and are present in an amount of 0.5-5 wt.%. Preferred Properties: The inorganic particles have mean particle size of 50-150 nm. Silver nanowires which are embedded in conductive polymer layers have a length variation of 1.5-15 mu m and diameter 40-150 nm. The resolution of printed lines, dots or structures is less than 90 mu m. Preferred Process: The etching paste is applied onto the surface by screen printing, gravure-printing, inkjetting, dispensing or micro-jetting. The substrate is heated for 10 seconds to 15 minutes at 20-170 degrees C, preferably for 5 minutes at 100 degrees C. The treated substrate is rinsed with deionized water or with a solvent and dried with dry air or with nitrogen flow.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The etching paste comprises a solvent chosen from water, mono- or polyhydric alcohols such as glycerol, 1,2-propanediol, 1,2-ethanediol, 2-propanol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 2-ethyl-1-hexenol, ethylene glycol, diethylene glycol and dipropylene glycol, ether such as ethylene glycol monobutyl ether, triethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether and dipropylene glycol monomethyl ether, ester such as (2,2-butoxy(ethoxy))ethyl acetate, isopropyl acetate, isopropyl formate, esters of carbonic acid such as propylene carbonate, ketone such as acetone, 2-butanone, acetophenone, methyl-2-hexanone, 2-octanone, 4-hydroxy-4-methyl-2-pentanone, pyrrolidone and 1-methyl-2-pyrrolidone, caprolactam, 1,3-dioxolane, 2-methyl-1,3-dioxolane and/or aldehyde such as acetaldehyde in an amount of 10-90 wt.%, preferably 15-85 wt.%.    TECHNOLOGY FOCUS - POLYMERS - Preferred Property: The organic particles have mean particle size of 0.5-20 mu m. Preferred Composition: The organic particles are present in the etching paste in an amount of 5-20 wt.%. The organic polymer particles are chosen from polystyrene, acrylic polymers, polyamide, polyimide, methacrylic polymer, melamine, urethane, benzoguanine and phenolic resin, silicone resin, micronized cellulose, fluorinated polymer (PTFE), polyvinyl difluoride, and micronized wax as filler and thickener. The plastic is polyurethane, polyethylene naphthalate (PEN) or polyethylene terephthalate (PET). The conductive polymer is chosen from poly(3-octylthiophene) (P3OT), poly(3-hexyl-thiophene) polymer (P3HT), poly(3,4-ethylene dioxythiophene) or other polythiophene derivatives and/or polyaniline polymers like poly(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene) (MDMO-PPV) or 1-(3-methoxycarbonyl)-propyl-1-phenyl(6,6)61C (PCBM), poly(3-hexyl-thiophene) polymer (P3HT)/(PCBM) and poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS).