{"id":102,"date":"2026-06-18T18:44:27","date_gmt":"2026-06-18T17:44:27","guid":{"rendered":"https:\/\/askthenozzle.com\/blog\/best-first-layer-settings-in-prusaslicer-the-exact-values-that-make-prints-stick\/"},"modified":"2026-06-29T23:47:49","modified_gmt":"2026-06-29T22:47:49","slug":"best-first-layer-settings-in-prusaslicer-the-exact-values-that-make-prints-stick","status":"publish","type":"post","link":"https:\/\/askthenozzle.com\/blog\/best-first-layer-settings-in-prusaslicer-the-exact-values-that-make-prints-stick\/","title":{"rendered":"Best First Layer Settings in PrusaSlicer: The Exact Values That Make Prints Stick"},"content":{"rendered":"<p>The first layer is where most prints live or die. Get it right and everything above it falls into line. Get it wrong and you&#8217;re peeling spaghetti off the bed an hour later. This guide gives you the <strong>best first layer settings in PrusaSlicer<\/strong> \u2014 real values, what each one does, and the gotchas that trip people up. No hand-waving, no &#8220;just lower your speed a bit&#8221;. Concrete numbers and the reasoning behind them.<\/p>\n<p>The settings and screens below are described as they appear in the <a href=\"https:\/\/askthenozzle.com\">ATN Slicer<\/a> \u2014 our free OrcaSlicer-based slicer with an AI print-doctor built right in, so bad settings and likely first-layer failures get flagged the moment you slice, before you waste filament. Because it&#8217;s an Orca fork, every setting name and location is identical to OrcaSlicer, and the same logic maps cleanly onto PrusaSlicer too \u2014 so whichever slicer brought you here, the values still apply. <a href=\"https:\/\/askthenozzle.com\">Download the ATN Slicer free for Windows \u2192<\/a><\/p>\n<p>One thing to understand up front: the ATN Slicer (like its OrcaSlicer parent, and unlike some others) broadly does what you tell it. If you specify a 0.20 mm first layer height, it calculates the flow and movement for 0.20 mm. It doesn&#8217;t quietly &#8220;help&#8221; by tweaking flows behind the scenes the way Simplify3D used to. That&#8217;s good news \u2014 it means these settings behave predictably \u2014 but it also means sloppy values produce sloppy first layers. There&#8217;s no safety net \u2014 though in the ATN Slicer the pre-flight engine will at least warn you before the print goes wrong.<\/p>\n<h2>First layer height: start at 0.20 mm<\/h2>\n<p>Original Prusa print profiles always use <strong>0.20 mm<\/strong> as the first layer height, regardless of the layer height you&#8217;ve chosen for the rest of the model. That&#8217;s the default for a reason. It&#8217;s thick enough for good flow and reliable squish, but not so thick that uneven cooling becomes a problem. Too thin and bed-surface uniformity starts to show through; too thick and the layer can cool unevenly.<\/p>\n<p>If you&#8217;re printing at a very fine layer height \u2014 say 0.10 mm for detail \u2014 keep the first layer at 0.20 mm anyway to boost bed adhesion. In the ATN Slicer you&#8217;ll find this under Quality \u2192 Layer height \u2192 Initial layer height, and you can enter the value two ways:<\/p>\n<ul>\n<li><strong>Absolute<\/strong> \u2014 e.g. <code>0.20<\/code> mm<\/li>\n<li><strong>Percentage<\/strong> of the default layer height \u2014 e.g. <code>150%<\/code><\/li>\n<\/ul>\n<p>(In PrusaSlicer the same control lives in Print Settings \u2192 Layers and perimeters.)<\/p>\n<p>A couple of hard limits to respect. Layer height should stay below 80% of the nozzle diameter, so with a 0.4 mm nozzle your practical ceiling is about 0.32 mm. The slicer won&#8217;t let you set a layer height above the nozzle diameter at all \u2014 it throws an error. And on MK3-class machines there&#8217;s a firmware floor: the minimum first layer height is around 0.15 mm, owing to the software endstops. Don&#8217;t try to go below that.<\/p>\n<blockquote>\n<p>Changing the first layer height will almost always require you to re-tune your live Z \/ first layer calibration on the printer. Adjust the value, then check the squish on a fresh print \u2014 don&#8217;t assume your old offset still applies.<\/p>\n<\/blockquote>\n<h2>First layer speed: slow it down, but be specific<\/h2>\n<p>Speed is the lever most people reach for, and rightly so. Lay material down too fast and the nozzle can drag through the previous pass on the way back, lifting it off the bed \u2014 especially once the plastic has cooled. The official Prusa troubleshooting move is to <strong>drop to about 75% of normal speed for the first three layers<\/strong>, then return to normal. The older Slic3r-era guidance of 30\u201350% is more aggressive but follows the same logic.<\/p>\n<p>In absolute terms, plenty of experienced users run the first layer at <strong>18\u201325 mm\/s<\/strong> for reliable adhesion. The perimeters are what matter most here \u2014 first-layer infill can run faster without much risk, but the outline that anchors the part to the bed benefits from going slow.<\/p>\n<h3>The catch: first layer speed is one setting<\/h3>\n<p>Here&#8217;s a limitation worth knowing. In the ATN Slicer, the dedicated initial-layer speed (Speed \u2192 Other layers \/ Initial layer speed) is a single value that applies to <em>everything<\/em> on that layer \u2014 you can&#8217;t natively split it by feature type. If you want slow perimeters but fast first-layer infill, you need a workaround using a <strong>height range modifier<\/strong>:<\/p>\n<ol>\n<li>Set the <strong>first layer speed to 100%<\/strong> in the Speed \u2192 Modifiers section. This is the crucial step \u2014 if you skip it, the modifier won&#8217;t override the first layer setting.<\/li>\n<li>Add a height range modifier to the object covering 0 to 0.20 mm (or whatever your first layer height is). In the ATN Slicer, right-click the object \u2192 Add height range modifier.<\/li>\n<li>Inside that modifier, add the features you want to control \u2014 Outer wall, Inner wall, Small perimeters, Solid infill \u2014 and set each speed independently.<\/li>\n<\/ol>\n<p>(PrusaSlicer users do exactly the same thing, with the features named External perimeters, Perimeters, Small perimeters and Solid infill.)<\/p>\n<p>Most people don&#8217;t need this. Set first layer speed to 20\u201325 mm\/s and move on. But if you&#8217;re chasing both adhesion and print time on big plates, the modifier route is how you get there.<\/p>\n<h2>First layer extrusion width: more contact, more grip<\/h2>\n<p>The more material touching the bed, the better the part holds. You can increase that contact by widening the first layer extrusion \u2014 in the ATN Slicer it&#8217;s under Quality \u2192 Line width \u2192 Initial layer (PrusaSlicer puts it in Print Settings \u2192 Advanced). A value of around <strong>200%<\/strong> is commonly recommended \u2014 but read the next sentence carefully, because this is where people get burned.<\/p>\n<p>The percentage is calculated from the <em>layer height<\/em>, not the nozzle diameter. So 200% only gives you a fat extrusion if your first layer height is high. Worked example: a 0.35 mm first layer at 200% width gives a nice fat 0.65 mm trace \u2014 exactly what you want. But set the first layer height to 0.10 mm and 200% gives you just 0.20 mm of width, which is <em>narrower than your nozzle<\/em>. That causes poor flow and a failed print.<\/p>\n<p>The safe approach: if you&#8217;re going to use a percentage width, only do it when your first layer height is already near its maximum. Otherwise enter a fixed value in millimetres (e.g. <code>0.5<\/code> mm with a 0.4 mm nozzle) so you know exactly what you&#8217;re getting.<\/p>\n<h2>First layer temperature: set it per filament<\/h2>\n<p>First layer temperature lives in the filament settings (Filament \u2192 Temperature in the ATN Slicer; Filament Settings \u2192 Temperature in PrusaSlicer), and almost every system filament profile already sets a different first layer temp from the rest of the print. That&#8217;s deliberate \u2014 a slightly hotter first layer flows better and bonds harder to the bed. Bump it 5\u201310 \u00b0C above your normal print temperature if you&#8217;re fighting adhesion. PLA typically anchors well at 210\u2013215 \u00b0C first layer; PETG benefits from a hotter, slower first layer because it&#8217;s so sensitive to squish and cooling.<\/p>\n<h2>The right order to fix a bad first layer<\/h2>\n<p>Don&#8217;t change five settings at once. Work through them in this order, which isolates causes instead of stacking guesses:<\/p>\n<ol>\n<li><strong>Bed levelling and live Z first.<\/strong> No setting compensates for a poorly trammed or mis-offset bed. Most &#8220;bad first layer&#8221; problems are mechanical, not slicer.<\/li>\n<li><strong>Thicker first layer height<\/strong> (back to 0.20 mm) if your bed surface is uneven.<\/li>\n<li><strong>Slower first layer speed<\/strong> (75% or ~20 mm\/s).<\/li>\n<li><strong>Wider first layer extrusion<\/strong> \u2014 fixed mm value, or 200% only at high layer heights.<\/li>\n<li><strong>Higher first layer temperature<\/strong>, last.<\/li>\n<\/ol>\n<p>If you&#8217;re not sure <em>which<\/em> of these is your problem, that&#8217;s exactly what the AI print-doctor in the <a href=\"https:\/\/askthenozzle.com\">ATN Slicer<\/a> is for \u2014 its Diagnose panel sits right beside the gcode preview, so you can upload a shot of the failure and get back the specific setting at fault. You can also use our standalone <a href=\"https:\/\/askthenozzle.com\/diagnose\">diagnose a failed print from a photo<\/a> tool in the browser, which returns a downloadable .ini patch for PrusaSlicer or OrcaSlicer. For material-specific deep dives, see our guides on <a href=\"https:\/\/askthenozzle.com\/blog\/first-layer-adhesion-problems-with-pla-the-real-causes-and-exact-fixes\/\">PLA first layer adhesion<\/a> and <a href=\"https:\/\/askthenozzle.com\/blog\/first-layer-adhesion-issues-with-petg-why-it-sticks-too-well-and-sometimes-not-at-all\/\">PETG first layer adhesion<\/a> \u2014 PETG in particular needs a different approach to squish. There&#8217;s also a full breakdown of <a href=\"https:\/\/askthenozzle.com\/blog\/prusaslicer-settings-to-fix-first-layer-problems-exact-values\/\">PrusaSlicer settings to fix first layer problems<\/a> with exact values, and if you run OrcaSlicer too, the equivalent <a href=\"https:\/\/askthenozzle.com\/blog\/orcaslicer-first-layer-adhesion-settings-the-exact-values-that-make-prints-stick\/\">OrcaSlicer first layer settings<\/a> \u2014 both of which map directly onto the ATN Slicer.<\/p>\n<h2>A solid baseline to copy<\/h2>\n<p>If you just want numbers to start from on a 0.4 mm nozzle, standard bed:<\/p>\n<ul>\n<li><strong>First layer height:<\/strong> 0.20 mm<\/li>\n<li><strong>First layer speed:<\/strong> 20\u201325 mm\/s (or 75% of normal)<\/li>\n<li><strong>First layer extrusion width:<\/strong> 0.5 mm fixed (not a percentage at this height)<\/li>\n<li><strong>First layer temperature:<\/strong> +5\u201310 \u00b0C over print temp, set per filament<\/li>\n<\/ul>\n<p>Slice with these in the <a href=\"https:\/\/askthenozzle.com\">ATN Slicer<\/a>, then dial in your live Z on a single-layer test before judging anything. Before you send a long print, the slicer&#8217;s built-in pre-flight engine will flag the failures that waste hours and filament the moment you slice \u2014 or you can run the gcode through our browser-based <a href=\"https:\/\/askthenozzle.com\/preflight\">gcode pre-flight checklist<\/a> separately. Related: our <a href=\"https:\/\/askthenozzle.com\/blog\/g-code-checker-before-printing-catch-failures-before-they-cost-you\/\">G-code checker before printing<\/a> guide explains exactly what to look for.<\/p>\n<h2>FAQ<\/h2>\n<h3>What is the best first layer height in PrusaSlicer?<\/h3>\n<p>0.20 mm. It&#8217;s the default in every Original Prusa profile because it gives reliable flow and squish without the uneven cooling you get from thicker layers. Keep it at 0.20 mm even when printing the rest of the model at 0.10 mm for finer detail. The same value and reasoning apply in the ATN Slicer and OrcaSlicer.<\/p>\n<h3>Why is my first layer extrusion width too thin at 200%?<\/h3>\n<p>Because the percentage is calculated from your layer height, not the nozzle diameter. At a 0.10 mm first layer, 200% is only 0.20 mm \u2014 narrower than a 0.4 mm nozzle, which starves flow. Use a fixed millimetre value (e.g. 0.5 mm) instead, or only use 200% when your first layer height is near maximum.<\/p>\n<h3>Can I set different first layer speeds for perimeters and infill?<\/h3>\n<p>Not natively \u2014 first layer speed is a single setting that applies to everything. To split it, set first layer speed to 100% in Speed \u2192 Modifiers, then add a height range modifier covering 0 to 0.20 mm and set per-feature speeds inside it. This works the same in the ATN Slicer, OrcaSlicer and PrusaSlicer. If you forget the 100% step, the modifier won&#8217;t take effect.<\/p>\n<h3>How slow should the first layer be?<\/h3>\n<p>Around 75% of your normal speed, or roughly 18\u201325 mm\/s in absolute terms. Slow perimeters matter most for anchoring the part; first-layer infill can run faster without much risk.<\/p>\n<p><strong>Related:<\/strong> <a href=\"https:\/\/askthenozzle.com\/blog\/how-to-get-better-first-layer-adhesion-the-settings-and-checks-that-actually-work\/\">How to Get Better First Layer Adhesion: The Settings and Checks That Actually Work<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The first layer is where most prints live or die. Get it right and everything above it falls into line. Get it wrong and you&#8217;re peeling spaghetti off the bed an hour later. This guide gives you the \u2026<\/p>\n","protected":false},"author":1,"featured_media":164,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-102","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/posts\/102","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/comments?post=102"}],"version-history":[{"count":2,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/posts\/102\/revisions"}],"predecessor-version":[{"id":191,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/posts\/102\/revisions\/191"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/media\/164"}],"wp:attachment":[{"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/media?parent=102"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/categories?post=102"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/askthenozzle.com\/blog\/wp-json\/wp\/v2\/tags?post=102"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}