Specify the number, skip the guesswork.<\/strong><\/p>\n\n\n\n Food service operators and packaging buyers seeking reliable grease barriers will find the measurement framework here, preparing them for the supplier comparison process that follows.<\/p>\n\n\n\n ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~<\/p>\n\n\n\n Grease stains are a small technical failure with an outsized brand effect. A wrap turns translucent, a bag leaves an oily shadow, and customers read that as “not clean” or “not food safe”\u2014even when the food is perfectly fine. One reason this happens is that “greaseproof” is often used as a label, not a measurable specification.<\/p>\n\n\n\n The burger wrapper looked fine leaving the line. But when the customer unwrapped it, oil had crept through, leaving a dark stain. They glanced at it, then at your logo. The wrapper was labeled “greaseproof,” but that label never specified how<\/em> greaseproof, or for how long.<\/p>\n\n\n\n This is why Kit Level<\/strong> exists. Think of it like SPF for sunscreen: a higher number means stronger protection against a specific threat. With Kit Level, you can compare food packaging paper<\/a> options objectively and stop relying on vague claims.<\/p>\n\n\n\n A Kit Level <\/strong>is a standardized grease-resistance rating for paper indicating the highest degree of aggressiveness from progressively more aggressive oil-solvent mixtures that the sheet can resist for a standard, fixed interval (typically 15 seconds) without penetration (TAPPI T 559 cm-12). The scale runs 1 to 12; higher numbers indicate resistance to liquids with lower surface tension.<\/p>\n\n\n\n This rating exists for comparability. Instead of trusting marketing terms like “greaseproof,” a stated Kit Level lets you compare options using the same measuring stick. The test method \u2014 TAPPI T 559<\/a> \u2014 is recognized globally, transforming subjective claims into verifiable specifications.<\/p>\n\n\n\n At Kit 1\u20134, paper generally resists mildly aggressive oils with higher surface tension\u2014suitable for dry, low-fat items (Smithers: Grease Resistance & Kit Rating<\/a>). Kit 5\u20138 handles moderate grease under normal serving conditions. Kit 9\u201312 resists aggressive, hot grease over extended hold times.<\/p>\n\n\n\n Illustrative ranges:<\/strong><\/p>\n\n\n\n These are starting points, not absolute rules. Your requirement depends on actual menu conditions\u2014temperature, pressure, and hold time all change the outcome. For detailed matching guidance, see the Menu-Match Matrix for food packaging paper<\/a>.<\/p>\n\n\n\n The test uses oil-solvent mixtures numbered 1\u201312, each more aggressive than the last. A lab applies each mixture to the paper surface and observes penetration within a set timeframe. The Kit Level is the highest-numbered mixture the paper resists without soaking through.<\/p>\n\n\n\n What this test tells you:<\/strong> How well the grease barrier holds under controlled, comparable conditions.<\/p>\n\n\n\n What it doesn’t tell you:<\/strong> How paper performs against steam or moisture. Kit Level measures grease resistance only\u2014not moisture management.<\/p>\n\n\n\n If packaging goes soggy from trapped steam, the solution is ventilation or moisture barriers, not higher Kit Level. See poly-coated vs. uncoated: choosing the right barrier<\/a> for guidance.<\/p>\n\n\n\n Kit Level appears alongside GSM (paper weight), Cobb value (water absorption), and coating type. Each addresses different performance dimensions.<\/p>\n\n\n\n GSM indicates weight and stiffness\u2014but heavy paper without barrier treatment still lets grease through. For a deeper understanding of how paper weight relates to menu items, see food packaging paper GSM explained<\/a>. Coating type describes the method, not the measured result. Kit Level quantifies grease-blocking performance specifically.<\/p>\n\n\n\n Heavier paper provides physical durability, but the Kit rating remains the primary metric for grease penetration.<\/p>\n\n\n\n Match Kit Level to three variables: grease load<\/strong>, serving temperature<\/strong>, and hold time<\/strong>.<\/p>\n\n\n\n A bakery wrapping cookies faces low grease at moderate temperatures\u2014Kit 3\u20135 typically suffices. A burger operation encounters moderate grease served warm\u2014Kit 6\u20138 addresses most standard items. Fried chicken operations deal with high grease, high heat, and delivery hold times\u2014Kit 9\u201312 becomes necessary.<\/p>\n\n\n\n The goal is fit-for-use, not maximizing.<\/strong> Kit 12 for dry cookies wastes money. Kit 4 for fried chicken fails in service.<\/p>\n\n\n\n Before committing to orders, run a simple hold test. For a step-by-step approach, see a simple 5-minute grease spot test to check your food packaging paper supply<\/a>.<\/p>\n\n\n\n Day-to-Day Example:<\/strong> A shift lead notices burger wrap stain-through at lunch. Rather than guessing, they request samples with stated Kit Levels and run a short hold test\u2014wrapping a burger, waiting the typical customer wait time, checking for penetration. Ten minutes of validation prevents production-scale mistakes.<\/p>\n\n\n\n “Greaseproof” means it has a Kit Level.<\/strong> Not necessarily. “Greaseproof” is marketing, not a measured spec. Always ask for the number. Learn more about why ‘food safe’ isn’t enough<\/a> and the hidden risks of generic labels.<\/p>\n\n\n\n Higher GSM means better grease resistance.<\/strong> GSM measures weight, not barrier performance. A 60 GSM paper with proper treatment can outperform untreated 80 GSM paper.<\/p>\n\n\n\n Mistaking grease resistance for moisture barriers. <\/strong>Sogginess is typically caused by water vapor; Kit ratings do not measure hydro-resistance (Cobb value).<\/p>\n\n\n\n Wax coatings equal greaseproof treatments.<\/strong> Wax softens under heat, reducing effectiveness above approximately 150\u00b0F (~65\u00b0C). See the wax paper trap<\/a> for details.<\/p>\n\n\n\n Heat affects grease resistance. <\/strong>High temperatures can change surface behavior and lower oil viscosity, making penetration more likely.<\/p>\n\n\n\n Flat lab tests predict real-world performance.<\/strong> Flat tests aren’t folds. Creases can create weak points that compromise the barrier where paper bends during wrapping or handling.<\/p>\n\n\n\nKit Level (Kit Rating)\u2014Simple Definition<\/h2>\n\n\n\n
![\"\u201cKit](\"https:\/\/www.paperindex.com\/academy\/wp-content\/uploads\/2026\/02\/kit-level-grease-resistance-test-timeline.png\")
<\/figure>\n\n\n\nWhat the 1\u201312 Numbers Mean in Plain English<\/h2>\n\n\n\n
\n
How a Kit Level Is Determined<\/h2>\n\n\n\n
Where Kit Level Fits on a Spec Sheet<\/h2>\n\n\n\n
How to Use Kit Level (The Buyer’s Mental Model)<\/h2>\n\n\n
![\"\u201cHow](\"https:\/\/www.paperindex.com\/academy\/wp-content\/uploads\/2026\/02\/how-to-use-kit-level-for-food-packaging.png\")
<\/figure>\n<\/div>\n\n\n
\n\n\n\n
\n\n\n\nCommon Misconceptions<\/h2>\n\n\n\n
\n\n\n\nThree Purchasing Approaches Compared<\/h2>\n\n\n\n