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Insulating varnish price is usually quoted in RMB/kg or USD/kg, but this figure assumes that every kilogram of varnish delivers the same amount of cured film. In reality:

• Solventless insulating varnishes have a solids content close to 100%: 1 kg of liquid leaves about 1 kg of dry film after curing;
• Solvent-borne varnishes typically run at 45–55% solids: 1 kg of liquid leaves only about 0.5 kg of dry film, with the rest evaporating during baking;
• Waterborne varnishes can run as low as 20% solids: 1 kg of liquid yields only about 0.2 kg of effective dry film.

The correct unit for comparison is therefore “cost per kg of dry film”, not “cost per kg of liquid”:

2.1 Resin system. Alkyd-amino systems use mature raw materials and short synthesis routes, forming the price baseline. Unsaturated polyester and epoxy-polyester systems cost more in raw materials but deliver higher thermal and mechanical performance. Waterborne epoxy systems require additional emulsification and dispersion processes, so formulation cost is not low — but solvent purchasing and VOC treatment costs are saved. Whether the resin is synthesized in-house also directly shapes the cost structure: an in-house producer eliminates one layer of resin trading markup.

2.2 Solids content. As shown in Section 1, solids content determines effective dry-film yield and is the first-weight parameter in any price conversion. High-solids products usually carry a higher unit price but a lower dry-film cost, and they achieve high fill in a single impregnation, reducing the number of dips.

2.3 Thermal class. Class B (130°C) and Class H (180°C) products (thermal classes defined by IEC 60085) use different resin and curing systems, and Class H raw materials cost significantly more. Buy the class you actually need — purchasing Class H varnish for a Class B application is pure budget waste.

2.4 Packaging and MOQ. Unit packaging cost differs clearly between large drums (180–200 kg) and small packs (4–20 kg); small-pack air-dry products for repair typically price above OEM bulk drums. MOQ, mixed-batch policy and hazardous-goods transport arrangements also affect the final delivered price.

2.5 Brand premium and channel layers. Imported brands pass through master distributors and multi-tier resellers, and their pricing includes brand maintenance and the amortized cost of global certification systems. At equivalent TDS data, a structural price gap exists between factory-direct supply and branded distribution. Lead time is also a hidden cost: 8–12 week lead times on imported products mean larger safety stock and more working capital tied up.

Energy cost: solvent-borne varnishes must first evaporate 45–55% solvent before curing completes, so energy consumption is higher than with solventless systems; air-dry types consume no baking energy at all. The larger your production volume, the more significant this gap becomes.

VOC and environmental compliance cost: solvent-borne and styrene-containing systems require exhaust capture and treatment facilities; waterborne systems use water as diluent, are non-flammable, and can substantially reduce investment in explosion-proof workshops and VOC treatment.

Impregnation cycles and labor: high-solids products reach the required fill in one impregnation; low-solids products (such as a 20%-solids waterborne varnish) require multiple dips, and each dip means labor and equipment time.

Lead time and inventory cost: 8–12 week lead times on imported products demand higher safety stock; factory-direct supply offers shorter lead times and batch-based replenishment, reducing working capital tied up in inventory.

Failure cost: rework and after-sales losses caused by selecting the wrong thermal class far exceed any price difference between varnishes — this is the most expensive item in TCO, and the reason the motor and transformer guides in this series keep stressing TDS-based selection.

Q1: Why do prices vary so much between suppliers for the same Class H varnish? Check three parameters first: solids content (which determines dry-film cost), whether the resin is synthesized in-house (which determines raw-material markup layers), and brand channel (master distributors and resellers each add a margin). When a significant price gap persists at the same class, solids content and performance data, it mostly comes from channel and brand premium rather than any performance difference.

Q2: Waterborne varnish has a low unit price — is it the cheapest option? Not necessarily. Waterborne varnishes have low solids content (CX936 at 20±2%), and dry-film cost = unit price ÷ solids content, which can exceed that of high-solids products; they also require multiple dips and more energy for water evaporation during curing. Their cost advantage sits on the VOC treatment and explosion-proof compliance side — evaluate on total cost of ownership.

Q3: Are imported brands always better than domestic ones? Compare the TDS data item by item: dielectric strength, thermal class, bond strength and thermal conductivity are all quantifiable, verifiable indicators. At equivalent data, factory-direct supply means the same performance at a lower price — Equal Quality, Factory Price.

Q4: How do I get an accurate quotation for my application? Three pieces of information are enough: your product type and thermal class requirement, your impregnation process (atmospheric / vacuum / VPI), and your monthly volume with packaging requirements. Send them to us, and our engineers will reply within 24 hours with selection advice, TDS and a quotation — free samples can also be arranged for verification.