<\/div>\n
Notched combs<\/h2>
The most widespread instrument is the notched comb (also called a wet film comb): a steel or plastic blade with calibrated notches of graduated height (for example 25, 50, 75, 100, 125, 150, 200 \u03bcm and upwards). The comb is placed perpendicular to the freshly painted surface; the highest notch that leaves a mark in the wet film identifies a thickness interval (the real thickness lies between the highest notch that does not touch and the lowest notch that does). Typical resolution is 25 \u03bcm for standard combs and 10-15 \u03bcm for high-resolution ones. Combs are available in metric and in mils (thousandths of an inch). <\/p>
Wheel gauges<\/h2>
There are also eccentric wheel instruments (wet film wheel gauges) which, thanks to a cam geometry with calibrated eccentricity, measure the thickness at finer resolution and continuously. They are used in high-quality industrial painting applications where the resolution of the standard comb is not sufficient. Most WFT instruments are of stainless steel or aluminum, with a laser-marked graduated surface for durability and legibility. Folding and pocket models are available for portability. <\/p>
Calculating the dry thickness<\/h2>
The wet thickness value (WFT) is converted into the expected dry thickness (DFT) through the paint’s volume solids ratio (Volume Solids %), declared by the manufacturer in the technical data sheet: DFT = WFT \u00d7 (Volume Solids \/ 100). For example, a paint with 50% volume solids applied at 200 \u03bcm WFT will give roughly 100 \u03bcm DFT once the solvent has evaporated. This predictive check allows immediate corrections to the rate of application and avoids the final coating being under- or over-thickness. <\/p>
Applications<\/h2>
WFT gauges are used in every industrial painting application where real-time control during application is required: corrosion protection of steel structures, painting of structural steelwork, sandblasting + primer + topcoat in marine and offshore systems, application of industrial floor coatings (epoxy, polyurethane), anti-slip treatments and intumescent fire-protection paints. They are also indispensable in the training courses for FROSIO- and NACE-certified industrial painters. <\/p>
Standards and selection criteria<\/h2>
WFT measurement is governed by standards ISO 2808-1 (method 1A comb, 1B wheel) and ASTM D4414. Calibration of combs is carried out with certified shims or by dimensional inspection of the notches on a CMM. The choice of instrument depends on the range of thicknesses applied (so as to cover the notches typical of the coating system), on the resolution required, on robustness (steel for intensive use, disposable plastic for economy) and on chemical resistance to the type of paint used. <\/p>","protected":false},"excerpt":{"rendered":"
Combs and notched instruments for measuring the thickness of paint and coatings while still wet.<\/p>\n","protected":false},"author":157040980,"featured_media":0,"parent":19361,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_yoast_wpseo_focuskw":"wet film thickness gauge","_yoast_wpseo_title":"Wet film thickness gauges (WFT) | RODER","_yoast_wpseo_metadesc":"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.","_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_wpcom_ai_launchpad_about_page":false,"_wpcom_ai_launchpad_gallery_page":false,"_wpcom_ai_launchpad_contact_page":false,"_wpcom_ai_launchpad_events_page":false,"_wpcom_ai_launchpad_video_page":false,"_wpcom_ai_launchpad_portfolio_piece":false,"_jetpack_hide_featured_image":false,"_jetpack_featured_image_duplicate_dismissed":0,"footnotes":""},"class_list":["post-22966","page","type-page","status-publish","hentry"],"yoast_head":"\n
Wet film thickness gauges (WFT) | RODER<\/title>\n<meta name=\"description\" content=\"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Wet film thickness gauges (WFT) | RODER\" \/>\n<meta property=\"og:description\" content=\"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/\" \/>\n<meta property=\"og:site_name\" content=\"RODER SRL\" \/>\n<meta property=\"article:modified_time\" content=\"2026-11-11T13:12:08+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/coating-thickness-and-surface-profile\\\/wet-film-thickness-gauges-wft\\\/\",\"url\":\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/coating-thickness-and-surface-profile\\\/wet-film-thickness-gauges-wft\\\/\",\"name\":\"Wet film thickness gauges (WFT) | RODER\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/#website\"},\"datePublished\":\"2026-05-13T13:42:03+00:00\",\"dateModified\":\"2026-11-11T13:12:08+00:00\",\"description\":\"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/coating-thickness-and-surface-profile\\\/wet-film-thickness-gauges-wft\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/coating-thickness-and-surface-profile\\\/wet-film-thickness-gauges-wft\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/coating-thickness-and-surface-profile\\\/wet-film-thickness-gauges-wft\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/roder.it\\\/en\\\/home\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Inspection\",\"item\":\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Coating thickness\",\"item\":\"https:\\\/\\\/roder.it\\\/en\\\/inspection\\\/coating-thickness-and-surface-profile\\\/\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"Wet film thickness gauges (WFT)\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/#website\",\"url\":\"https:\\\/\\\/roder.it\\\/en\\\/\",\"name\":\"RODER SRL\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/roder.it\\\/en\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/#organization\",\"name\":\"RODER SRL\",\"url\":\"https:\\\/\\\/roder.it\\\/en\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/roder.it\\\/wp-content\\\/uploads\\\/2019\\\/05\\\/logo_roder_standard_sfondo_bianco.png\",\"contentUrl\":\"https:\\\/\\\/roder.it\\\/wp-content\\\/uploads\\\/2019\\\/05\\\/logo_roder_standard_sfondo_bianco.png\",\"width\":691,\"height\":80,\"caption\":\"RODER SRL\"},\"image\":{\"@id\":\"https:\\\/\\\/roder.it\\\/en\\\/#\\\/schema\\\/logo\\\/image\\\/\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Wet film thickness gauges (WFT) | RODER","description":"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/","og_locale":"en_US","og_type":"article","og_title":"Wet film thickness gauges (WFT) | RODER","og_description":"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.","og_url":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/","og_site_name":"RODER SRL","article_modified_time":"2026-11-11T13:12:08+00:00","twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/","url":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/","name":"Wet film thickness gauges (WFT) | RODER","isPartOf":{"@id":"https:\/\/roder.it\/en\/#website"},"datePublished":"2026-05-13T13:42:03+00:00","dateModified":"2026-11-11T13:12:08+00:00","description":"Comb and wheel gauges for measuring the wet film thickness (WFT) of freshly applied paints and coatings, according to ISO 2808.","breadcrumb":{"@id":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/wet-film-thickness-gauges-wft\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/roder.it\/en\/home\/"},{"@type":"ListItem","position":2,"name":"Inspection","item":"https:\/\/roder.it\/en\/inspection\/"},{"@type":"ListItem","position":3,"name":"Coating thickness","item":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/"},{"@type":"ListItem","position":4,"name":"Wet film thickness gauges (WFT)"}]},{"@type":"WebSite","@id":"https:\/\/roder.it\/en\/#website","url":"https:\/\/roder.it\/en\/","name":"RODER SRL","description":"","publisher":{"@id":"https:\/\/roder.it\/en\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/roder.it\/en\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/roder.it\/en\/#organization","name":"RODER SRL","url":"https:\/\/roder.it\/en\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/roder.it\/en\/#\/schema\/logo\/image\/","url":"https:\/\/roder.it\/wp-content\/uploads\/2019\/05\/logo_roder_standard_sfondo_bianco.png","contentUrl":"https:\/\/roder.it\/wp-content\/uploads\/2019\/05\/logo_roder_standard_sfondo_bianco.png","width":691,"height":80,"caption":"RODER SRL"},"image":{"@id":"https:\/\/roder.it\/en\/#\/schema\/logo\/image\/"}}]}},"jetpack_likes_enabled":false,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/PaWZeX-5Yq","jetpack-related-posts":[{"id":36219,"url":"https:\/\/roder.it\/en\/news\/paints-and-coatings\/","url_meta":{"origin":22966,"position":0},"title":"Paints and coatings","author":"GSM","date":"2 November 2026","format":false,"excerpt":"Painting, galvanising and coatings: dry and wet film thickness, adhesion, gloss, blast profile and application conditions.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"strumenti di misura per la misura di forza di adesione di nastri adesivi e colle","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2021\/03\/checkline_force_gauge_gauges_g1045_1_masterimage-3.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2021\/03\/checkline_force_gauge_gauges_g1045_1_masterimage-3.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2021\/03\/checkline_force_gauge_gauges_g1045_1_masterimage-3.png?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":19361,"url":"https:\/\/roder.it\/en\/inspection\/coating-thickness-and-surface-profile\/","url_meta":{"origin":22966,"position":1},"title":"Coating thickness","author":"GSM","date":"13 May 2026","format":false,"excerpt":"Instruments for measuring the thickness of paint and coatings, blast profile, surface contamination and coating adhesion.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Kit Tramex per rivestimenti su calcestruzzo: Cctka concrete coatings installer tech kit no text","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/tramex-kit_concrete_coatings-cctka_concrete_coatings_installer_tech_kit_no_text-web_image-1200x1200-1.webp?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/tramex-kit_concrete_coatings-cctka_concrete_coatings_installer_tech_kit_no_text-web_image-1200x1200-1.webp?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/tramex-kit_concrete_coatings-cctka_concrete_coatings_installer_tech_kit_no_text-web_image-1200x1200-1.webp?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/tramex-kit_concrete_coatings-cctka_concrete_coatings_installer_tech_kit_no_text-web_image-1200x1200-1.webp?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/tramex-kit_concrete_coatings-cctka_concrete_coatings_installer_tech_kit_no_text-web_image-1200x1200-1.webp?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":14468,"url":"https:\/\/roder.it\/controlli\/spessori-di-rivestimenti-e-profilo-di-superficie\/spessimetri-film-umido-wft\/","url_meta":{"origin":22966,"position":2},"title":"Spessimetri film umido (WFT)","author":"GSM","date":"13 May 2026","format":false,"excerpt":"Pettini e strumenti notched per misura di spessore di vernice e rivestimenti applicati ancora umidi.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":36629,"url":"https:\/\/roder.it\/en\/inspection\/corrosion-and-wall-integrity\/","url_meta":{"origin":22966,"position":3},"title":"Corrosion and wall integrity","author":"GSM","date":"7 July 2026","format":false,"excerpt":"Corrosion and wall integrity Corrosion and wall integrity of tanks, pipes, hulls and metal structures are checked by measuring the residual metal thickness, the continuity of protective coatings and the tightness of bolted joints. This section brings together the instruments for these checks, in the plant and on site. On\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Spessimetro digitale a ultrasuoni Dakota NDT ZX6 con datalogger per misure di spessore e corrosione","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/dakota_ndt-zx6-strumento_zx6dl_strumento_ad_ultrasuoni_per_misure_di_spessore_e_corrosione-web_image-680x680-1.webp?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/dakota_ndt-zx6-strumento_zx6dl_strumento_ad_ultrasuoni_per_misure_di_spessore_e_corrosione-web_image-680x680-1.webp?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/dakota_ndt-zx6-strumento_zx6dl_strumento_ad_ultrasuoni_per_misure_di_spessore_e_corrosione-web_image-680x680-1.webp?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":17990,"url":"https:\/\/roder.it\/en\/inspection\/","url_meta":{"origin":22966,"position":4},"title":"Inspection","author":"GSM","date":"13 May 2026","format":false,"excerpt":"RODER \u00b7 Industrial inspection and measurement Industrial inspection and measurement The Inspection section brings together the pages dedicated to the physical quantities measured in quality control and industrial process control: dimensions and geometry, thickness, speed, force and torque, hardness, temperature, humidity, pressure, defects and vibration. The approach is centred on\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Vision check dynamic controllo di difetti di schede elettroniche e assemblati meccanici","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/07\/visio_check_dynamic_per_ispezione_linee_a_pallet.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/07\/visio_check_dynamic_per_ispezione_linee_a_pallet.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/07\/visio_check_dynamic_per_ispezione_linee_a_pallet.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/07\/visio_check_dynamic_per_ispezione_linee_a_pallet.png?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/07\/visio_check_dynamic_per_ispezione_linee_a_pallet.png?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/07\/visio_check_dynamic_per_ispezione_linee_a_pallet.png?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":22894,"url":"https:\/\/roder.it\/en\/inspection\/material-thickness\/thickness-gauges-for-thin-sheet-foil-and-tape\/","url_meta":{"origin":22966,"position":5},"title":"Thickness gauges for thin sheet, foil and tape","author":"GSM","date":"13 May 2026","format":false,"excerpt":"Precision instruments for measuring film and thin plastic and metal sheet, including roller models.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Spessimetro a forcella digitale Kaefer modello JD50","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/kaefer-jd50-spessimetro_a_forcella_digitale_jd50-web_image-1000x1000-1.webp?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/kaefer-jd50-spessimetro_a_forcella_digitale_jd50-web_image-1000x1000-1.webp?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/kaefer-jd50-spessimetro_a_forcella_digitale_jd50-web_image-1000x1000-1.webp?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/07\/kaefer-jd50-spessimetro_a_forcella_digitale_jd50-web_image-1000x1000-1.webp?resize=700%2C400&ssl=1 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/pages\/22966","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/users\/157040980"}],"replies":[{"embeddable":true,"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/comments?post=22966"}],"version-history":[{"count":5,"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/pages\/22966\/revisions"}],"predecessor-version":[{"id":40145,"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/pages\/22966\/revisions\/40145"}],"up":[{"embeddable":true,"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/pages\/19361"}],"wp:attachment":[{"href":"https:\/\/roder.it\/en\/wp-json\/wp\/v2\/media?parent=22966"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"banner](\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/banner_technical_support_choose_products-1024x213.png\")