LOW-E Coating Guide

All product lines — Guardian SunGuard (soft), Vitro Solarban & Sungate, Pilkington Energy Advantage & Soft Coat

Soft Coat vs. Hard Coat: The Foundation
Two Different Manufacturing Processes

All LOW-E coatings do the same job: reflect infrared heat while letting visible light through. The difference is when and how the coating is applied during manufacturing.

Soft Coat (Sputtered)
When: After glass is made (post-production)

How: Applied in a vacuum chamber. Multiple ultra-thin metallic layers (often 3-15 layers) are built up sequentially.

Result: Delicate, multi-layer coating. Can be scratched if handled roughly. Must be protected inside an IGU (insulated glass unit).

Performance: Superior thermal (U-0.22-0.24). More formulation options. Better solar control options.

Lead Time: Longer (7-10 weeks). Requires specialty coating equipment.

Temperature Stability: Sensitive to extreme heat (650°C+). Can yellow if tempered aggressively.
Hard Coat (Pyrolytic)
When: During float glass production (inline)

How: Applied while glass is still hot. Coating fuses directly to the glass surface as it cools. Becomes part of the glass surface.

Result: Permanent, durable coating. Resists scratching and abrasion. Can be handled and processed aggressively.

Performance: Good thermal (U-0.30-0.31). Limited formulations due to manufacturing constraints.

Lead Time: Faster (4-7 weeks). Can be tempered easily because coating is permanent.

Temperature Stability: Stable through high heat. No yellowing risk on tempering. Flexible temper sequence.
At Pulp: You Carry Both
Your Inventory Reality

Pulp stocks both soft and hard coats because different projects demand different solutions. You prefer hardcoat strategically, but softcoat exists for projects where the thermal gain justifies the complexity and cost.

  • Soft Coat: Guardian SunGuard (all variants) + Vitro Solarban (all variants) + Pilkington soft coat (double/triple silver sputter)
  • Hard Coat: Vitro Sungate + Pilkington Energy Advantage
Guardian SunGuard (All Soft Coat)
Guardian makes only soft coat LOW-E. All SunGuard products use sputter deposition. They don't manufacture hardcoat LOW-E. Single-silver, double-silver, and triple-silver variants are all soft coat.
Guardian SunGuard Product Lines
SunGuard HP Neutral (Single Silver)
Soft Coat
Description
Commercial range. Single silver layer. Balanced solar control + thermal insulation.
U-Value Range
0.28-0.31 depending on configuration
SHGC
0.40-0.43
Available On
Clear glass and UltraClear (low-iron)
Common Use
Mid-range commercial. Decent solar control without extreme performance positioning.
SunGuard SNR/SNX (Double & Triple Silver)
Soft Coat
Examples
SNR 35, SNR 50, SNX 70+
Description
Double and triple silver variants. Higher performance. More selective solar control options.
U-Value Range
0.25-0.31
Common Use
Premium commercial. Architect-specified for aesthetic and performance precision.
Lead Time
6-7 weeks typical
SunGuard ClimaGuard (Residential/Lower SHGC)
Soft Coat
Description
Guardian's residential soft coat. Lower solar heat gain for hot climates.
SHGC Range
0.25-0.32 (lower = more solar rejection)
Availability at Pulp
Less common (commercial focus), but available on request
Guardian Strategic Note

Guardian's commercial positioning is all soft coat. If you want hardcoat performance from a premium manufacturer, you don't go to Guardian—you go to Vitro Sungate or Pilkington Energy Advantage. Guardian's strength is in the soft coat formulations (SunGuard variants offer more options than competitors).

Vitro: Solarban (Soft) + Sungate (Hard)
Vitro offers both. Solarban is their soft coat line (triple-silver, highly specified). Sungate is their hardcoat line (pyrolytic, heating-dominated climates).
Vitro Solarban (Soft Coat)
Product Type U-Value SHGC VLT Best For
Solarban 60 Triple Silver 0.28 0.26 70% Classic solar control. Balanced performance. Proven 25+ years.
Solarban 65 Triple Silver 0.27 0.29 72% Modern update to 60. Better thermal. Meets stricter energy codes.
Solarban 70 Triple Silver 0.28 0.28 69% Most specified in North America. Best balance of VLT + solar control.
Solarban 72 Triple Silver 0.27 0.30 75% Even more transparent than 70. More light, slightly less solar control.
Solarban 90 Quad Silver 0.26 0.27 73% Latest evolution. Neutral appearance (clear-like). High performance. Premium.
Solarban R67, R100 Reflective Options 0.25-0.27 0.23-0.25 42-50% Reflective variants. Extreme solar control. Limited daylighting.
Solarban Strategic Use

Solarban 70 is your default soft coat. Most specified in North America. Architects know it. Proven field performance. If an architect specifies "Solarban," they almost always mean 70. Use 60 for older projects or budget-conscious applications. Use 90 for premium projects demanding neutral aesthetics.

Vitro Sungate (Hard Coat)
Sungate 400 (& Other Sungate Variants)
Hard Coat (Pyrolytic)
Description
Vitro's hardcoat line. Passive LOW-E (heating-dominated climate focus). Applied inline during float production.
U-Value
0.30-0.35 range
SHGC
0.38-0.48
Lead Time
4-6 weeks (faster than soft coat)
Geographic Focus
Heating-dominated climates (Canada, northern US). Less specified in hot climates.
Practical Use at Pulp
Your hardcoat option from Vitro. Cheaper alternative to Solarban when project doesn't demand strong solar control.
Pilkington: Energy Advantage (Hard) + Soft Coat Options
Pilkington manufactures both. Energy Advantage is their workhorse hardcoat. Soft coat options (double/triple silver sputter) available but less marketed than hard coat.
Pilkington Energy Advantage (Hard Coat)
Pilkington Energy Advantage™
Hard Coat (Pyrolytic)
Description
Pyrolitically on-line coated. Applied during float production. Fused to glass surface. Durable hardcoat.
U-Value
0.30-0.32
SHGC
0.38-0.42
Available On
Clear glass and Pilkington Optiwhite™ (low-iron)
Lead Time
6-8 weeks
Flexibility
Temper before or after coating. Can be used surface #2 only or #2 + #4 for even better U-factor.
Use at Pulp
Go-to hardcoat option. Solid performer. Less architect recognition than Vitro Sungate but excellent durability and reliability.
Pilkington Soft Coat Options
Pilkington Double/Triple Silver Sputter Coat
Soft Coat
Description
Sputter-applied soft coat. Double and triple silver options available. Not as widely marketed as Energy Advantage.
U-Value Range
0.22-0.28 (depends on configuration)
SHGC Range
0.25-0.32
Lead Time
7-10 weeks typical
Use at Pulp
When architect specifies Pilkington soft coat or you need superior thermal from Pilkington. Less common than Energy Advantage but available.
Why Pulp Prefers Hardcoats (Even Though You Stock Softcoats)
The Reality

You carry both because the market demands both. But hardcoat is your strategic preference for most projects. Here's why.

1. Lead Time Advantage
Hardcoat: 4-7 weeks
Vitro Sungate (4-6w) and Pilkington Energy Advantage (6-8w) are faster than soft coat (7-10w).

Competitive Win: When an architect needs specs in 5 weeks, hardcoat is viable. Soft coat is not. You can promise delivery; hardcoat makes it possible.
2. No Yellowing Risk
Hardcoat: Stable on tempering (650°C+)
Fused coating won't yellow. Temper before or after—doesn't matter.

Softcoat: Yellowing risk at 650°C+
You must test in your furnace. You must notify customers of risk. You must manage it.

Operational Win: Hardcoat simplifies your process and eliminates a liability.
3. Process Simplicity
Hardcoat: Order → Receive → Cut/Shape → Temper if needed → Fab IGU → Deliver

Softcoat (especially Pilkington): Order → Receive → Cut/Shape → Fab IGU *without temper* → Send to coater → Receive back → Temper if needed → Final QC → Deliver

Operational Win: Hardcoat keeps your IGU assembly sequence simple. No mid-process shipping to external coater.
4. Durability & Field Reliability
Hardcoat: Fused to glass. Resists scratching, abrasion, environmental stress. Proven in field for 20+ years.

Softcoat: Delicate multi-layer coating. Can be scratched during handling if not careful. Requires more careful shipping and handling protocols.

Risk Win: Hardcoat = fewer field callbacks and damage claims.
5. Cost Efficiency
Hardcoat: Cheaper material cost. Faster lead time = lower carrying cost. No yellowing risk = no rework/replacement cost.

Softcoat: 20-30% material premium. Longer lead time. Potential yellowing cost.

Margin Win: Hardcoat margin is better. You can price more competitively or keep higher margin.
When Softcoat Still Makes Sense

Architect-specified: "Solarban 70" or "Guardian SunGuard" required → You build it.

Extreme thermal requirement: U-factor must be 0.24 or better → Softcoat (0.22-0.24) is only way to achieve it without expensive window frames/triple-pane IGU.

Premium project: High-end commercial where 20-30% glass premium is acceptable and architect demands performance positioning → Softcoat signals "we chose the best thermal."

Otherwise: Default to hardcoat. It's faster, safer, simpler, and cheaper.

Decision Guide: Which Product to Recommend
Your Default Logic

Start with hardcoat. Move to softcoat only if the project has a specific requirement that hardcoat can't meet.

Standard commercial, no thermal requirement, fast timeline
→ Vitro Sungate (hardcoat)
4-6 week lead time. U-0.30. Solid performer. Cost-efficient. Zero yellowing risk.
Mid-rise commercial, good thermal desired, architect open to options
→ Pilkington Energy Advantage (hardcoat)
6-8 weeks. U-0.30-0.32. Mid-cost. Excellent durability. Alternative to Vitro (both hardcoat, similar performance).
Architect specifies "Solarban" or specific soft coat product
→ Build what they specified
Solarban (usually 70), Guardian SunGuard variants, or Pilkington soft coat. Respect the spec. But flag lead time (7-10 weeks) and yellowing risk if tempering is planned. Confirm the architect understands the tradeoffs.
High-end commercial, thermal target is U-0.24 or better
→ Softcoat required (likely Solarban 70 or 90)
7-10 weeks. U-0.26-0.28. Accept the cost premium (20-30% higher). Accept the complexity. But test for yellowing in your furnace first.
Rush job—specs needed in 4 weeks
→ Vitro Sungate (hardcoat, 4-6 weeks is your only play)
Softcoat won't make the timeline. Hard coat is your competitive advantage here.
Softcoat specified but tempering happens at high temp (700°C+) in your furnace
→ Call the manufacturer, test a sample, OR push back to hardcoat
Yellowing risk is real. Either: (1) Confirm batch is temper-tested, (2) Test sample in your furnace, or (3) Recommend hardcoat alternative (U-0.30 is close to soft U-0.26 and avoids the risk entirely).
Cost-sensitive project, no special thermal, architect flexible
→ Vitro Sungate (hardcoat)
Cheapest hardcoat option. Still solid performance. No risk. Clear winner on margin.