{"id":405,"date":"2026-01-11T01:18:03","date_gmt":"2026-01-10T23:18:03","guid":{"rendered":"https:\/\/3dprint.lviv.ua\/post-processing-3d-printed-parts\/"},"modified":"2026-10-09T22:04:21","modified_gmt":"2026-10-09T19:04:21","slug":"post-processing-3d-printed-parts","status":"publish","type":"post","link":"https:\/\/3dprint.lviv.ua\/en\/post-processing-3d-printed-parts\/","title":{"rendered":"Post-processing 3D-printed parts \u2014 sanding and painting"},"content":{"rendered":"<h2>Post-processing 3D-printed parts: how to get a perfect surface<\/h2>\n<p>3D printing lets you make parts of almost any shape, but items fresh off the printer don\u2019t always look perfect. Visible layers, support marks, bumps \u2014 all of these can be removed with <strong>post-processing<\/strong>. In this article we look at the main techniques for sanding, priming, painting and other ways of finishing 3D-printed parts.<\/p>\n<h2>When post-processing is needed and when it isn\u2019t<\/h2>\n<p>Not every 3D-printed item needs extra finishing. Knowing this will save you time and money.<\/p>\n<h3>Post-processing is needed if:<\/h3>\n<ul>\n<li>The item will be on display and needs to look good (decor, gifts, cosplay)<\/li>\n<li>A smooth surface is needed for functional reasons (sealing, sliding)<\/li>\n<li>The part consists of several pieces that need to be glued with the seams hidden<\/li>\n<li>The item needs painting in a specific colour or a protective coating<\/li>\n<\/ul>\n<h3>Post-processing isn\u2019t necessary if:<\/h3>\n<ul>\n<li>The part is hidden inside a mechanism and can\u2019t be seen<\/li>\n<li>It\u2019s a functional prototype for testing shape and size<\/li>\n<li>The layer texture is acceptable or even desirable<\/li>\n<li>The item was printed at high resolution and already looks good enough<\/li>\n<\/ul>\n<h2>Sanding: the basis of any post-processing<\/h2>\n<p>Sanding is the first and most important stage of surface finishing. It smooths visible layer lines and prepares the part for priming or painting.<\/p>\n<h3>Step-by-step sanding technique<\/h3>\n<p><strong>Stage 1: Coarse sanding (100\u2013150 grit)<\/strong><\/p>\n<p>Start with <strong>100\u2013150<\/strong> grit sandpaper. This stage removes the biggest bumps, support marks and obvious print defects. Use even strokes and don\u2019t press too hard so you don\u2019t deform the part.<\/p>\n<p><strong>Stage 2: Medium sanding (300\u2013400 grit)<\/strong><\/p>\n<p>Move on to <strong>300\u2013400<\/strong> paper. Here you smooth out the marks from the previous stage and make the surface more uniform. The visible layer lines start to disappear at this stage.<\/p>\n<p><strong>Stage 3: Fine sanding (600\u2013800 grit)<\/strong><\/p>\n<p>Finish with <strong>600\u2013800<\/strong> paper. <strong>Wet sanding<\/strong> is recommended \u2014 keep the sandpaper wet while you work. This reduces dust, stops the abrasive from clogging and gives a smoother surface.<\/p>\n<p><strong>Tip:<\/strong> sand in circular motions and rinse the part with water regularly to check the result. PLA and ABS sand well; PETG is a bit harder because it\u2019s tougher.<\/p>\n<h2>Priming: preparing for paint<\/h2>\n<p>After sanding, the surface may have small scratches and pores. <strong>Primer<\/strong> fills these defects and creates an even base for paint.<\/p>\n<ul>\n<li>Use <strong>filler primer<\/strong> in a spray can \u2014 it\u2019s specially designed to fill small imperfections<\/li>\n<li>Apply <strong>2\u20133 thin coats<\/strong> from 20\u201330 cm away, letting each coat dry for 15\u201320 minutes<\/li>\n<li>Once dry, go over it lightly with <strong>600\u2013800 grit<\/strong> sandpaper for a perfectly smooth finish<\/li>\n<li>Repeat the prime-and-sand cycle again if needed<\/li>\n<\/ul>\n<p>Primer also helps reveal defects that aren\u2019t visible on an unpainted surface.<\/p>\n<h2>Painting: giving the item its final look<\/h2>\n<h3>Spray painting<\/h3>\n<p>Spray paint is the most popular way to paint 3D-printed parts. It gives an even coat with no brush marks.<\/p>\n<ul>\n<li>Choose <strong>acrylic spray paint<\/strong> \u2014 it adheres well to plastic<\/li>\n<li>Apply <strong>3\u20134 thin coats<\/strong> instead of one thick one \u2014 this prevents runs<\/li>\n<li>Wait <strong>10\u201315 minutes<\/strong> between coats<\/li>\n<li>Work in a well-ventilated room or outdoors<\/li>\n<li>Hold the can <strong>25\u201330 cm<\/strong> from the surface<\/li>\n<\/ul>\n<h3>Brush painting<\/h3>\n<p>A brush suits small details, figurines and pieces that need several colours.<\/p>\n<ul>\n<li>Use <strong>acrylic model paints<\/strong> (Vallejo, Citadel, Tamiya)<\/li>\n<li>Apply paint in thin layers, avoiding excess<\/li>\n<li>Use a <strong>flat brush<\/strong> for large areas and a <strong>fine round brush<\/strong> for details<\/li>\n<li>You can mix colours to get the shade you want<\/li>\n<\/ul>\n<h3>Finishing with varnish<\/h3>\n<p>After painting, it\u2019s best to apply a <strong>protective varnish<\/strong> \u2014 matte or gloss, depending on the effect you want. Varnish protects the paint from scratches, moisture and UV.<\/p>\n<h2>Acetone smoothing (ABS only)<\/h2>\n<p>If a part is printed in <strong>ABS plastic<\/strong>, there\u2019s a unique smoothing method \u2014 <strong>acetone vapour treatment<\/strong>. Acetone dissolves the surface of ABS, creating a smooth, almost glossy effect.<\/p>\n<h3>How to do it:<\/h3>\n<ul>\n<li>Put a paper towel soaked in acetone at the bottom of an airtight container<\/li>\n<li>Place the part on a stand inside the container (not touching the liquid)<\/li>\n<li>Close the container and leave it for <strong>15\u201360 minutes<\/strong>, depending on the effect you want<\/li>\n<li>Check the process every 10 minutes \u2014 overdoing it can blur fine details<\/li>\n<\/ul>\n<p><em><strong>Important:<\/strong> this method works <strong>only with ABS<\/strong>. PLA, PETG and other materials don\u2019t react to acetone. Work in a well-ventilated room and use protective equipment. You can compare the properties of different materials on the <a href=\"https:\/\/3dprint.lviv.ua\/en\/materials\/\">Materials<\/a> page.<\/em><\/p>\n<h2>Epoxy coating<\/h2>\n<p>For a strong, water-resistant and perfectly smooth coating, you can use <strong>epoxy resin<\/strong>. This method works with any material.<\/p>\n<ul>\n<li>Mix the epoxy resin with the hardener according to the instructions<\/li>\n<li>Apply a thin layer with a brush<\/li>\n<li>Let it cure fully (usually <strong>24\u201348 hours<\/strong>)<\/li>\n<li>Sand and apply another coat if needed<\/li>\n<\/ul>\n<p>An epoxy coating adds strength, makes the item waterproof and gives it a pleasant smooth texture. It\u2019s ideal for functional parts and items that come into contact with moisture.<\/p>\n<h2>Gluing and assembling multi-part items<\/h2>\n<p>Large or complex parts are often printed in several pieces that are joined afterwards. The main methods:<\/p>\n<ul>\n<li><strong>Superglue (cyanoacrylate)<\/strong> \u2014 a quick bond, suitable for PLA and ABS<\/li>\n<li><strong>Epoxy glue<\/strong> \u2014 a strong bond that can fill gaps<\/li>\n<li><strong>Welding with a soldering iron<\/strong> \u2014 joining plastic parts by melting them<\/li>\n<li><strong>Mechanical fasteners<\/strong> \u2014 bolts, nuts, threaded inserts<\/li>\n<\/ul>\n<p>After gluing, the seams can be hidden with filler, sanded and painted so the item looks like one solid piece.<\/p>\n<h2>Summary: a post-processing plan<\/h2>\n<p>Here\u2019s the general sequence for full post-processing of a 3D-printed part:<\/p>\n<ul>\n<li><strong>1.<\/strong> Remove supports and clean up the remnants<\/li>\n<li><strong>2.<\/strong> Coarse sanding (100\u2013150 grit)<\/li>\n<li><strong>3.<\/strong> Medium sanding (300\u2013400 grit)<\/li>\n<li><strong>4.<\/strong> Fine wet sanding (600\u2013800 grit)<\/li>\n<li><strong>5.<\/strong> Primer (2\u20133 coats)<\/li>\n<li><strong>6.<\/strong> Sanding the primer (600\u2013800 grit)<\/li>\n<li><strong>7.<\/strong> Painting (3\u20134 thin coats)<\/li>\n<li><strong>8.<\/strong> Protective varnish<\/li>\n<\/ul>\n<p>You don\u2019t have to do every stage \u2014 pick the ones that match your needs. For functional parts, sanding alone is often enough, while the full cycle is needed for display or decorative items.<\/p>\n<p><strong>Need professional post-processing of 3D-printed parts?<\/strong> At <a href=\"https:\/\/3dprint.lviv.ua\/en\/contact\/\">3dprint.lviv.ua<\/a> you can order printing with finishing \u2014 sanding, priming and painting. Get in touch to discuss your order and get advice on the best finishing option.<\/p>\n<h2>Order 3D printing<\/h2>\n<p>Need quality 3D printing? <a href=\"https:\/\/3dprint.lviv.ua\/en\/materials\/\">printing materials<\/a>. <a href=\"https:\/\/3dprint.lviv.ua\/en\/3d-printing-services\/\">order post-processing<\/a>. <a href=\"https:\/\/3dprint.lviv.ua\/en\/prices\/\">prices<\/a>. Delivery across Ukraine by Nova Poshta.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Post-processing 3D-printed parts: how to get a perfect surface 3D printing lets you make parts of almost any shape, but items fresh off the printer don\u2019t always look perfect. Visible layers, support marks, bumps \u2014 all of these can be removed with post-processing. In this article we look at the main techniques for sanding, priming, [&hellip;]<\/p>\n","protected":false},"author":0,"featured_media":342,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-405","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-guides"],"_links":{"self":[{"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/posts\/405","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/comments?post=405"}],"version-history":[{"count":1,"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/posts\/405\/revisions"}],"predecessor-version":[{"id":478,"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/posts\/405\/revisions\/478"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/media\/342"}],"wp:attachment":[{"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/media?parent=405"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/categories?post=405"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/3dprint.lviv.ua\/en\/wp-json\/wp\/v2\/tags?post=405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}