1. Leave your new parts uncleaned in the plastic shipping bag until you are ready to use them. "Fine Detail" acrylic plastic parts come to you protected by a very thin layer of oil. Once the oil has been removed, "Fine Detail" acrylic plastic may be sensitive to prolonged oxygen exposure. Before painting, clean your new parts with a mild water-based detergent like "Dawn", "Fairy", or "Simple Green" in water. Let your parts soak for a few hours to remove any wax.
2. Place your "Fine Detail" acrylic plastic parts in direct sunlight or under an ultra-violet light (UV) lamp or fluorescent lamp for several hours (more is better) to fully chemically harden the plastic.
3. If necessary, smooth "Fine Detail" acrylic plastic surfaces with an "air eraser" (click here to see one example). Use common household baking soda as the grit. Smooth "Versatile Plastic", a kind of nylon, with thin layers of primer meant for nylon.
4. Paint your parts soon after cleaning. Use the correct primer, paint and paint thinner for the type of plastic your part is printed in. Thinners containing acetone, acetate or methyl ethyl ketone (MEK) can damage "Fine Detail" acrylic plastic.
Material Selection Advice: some products are available in more than one material. For static display models, Frosted Detail acrylic plastic and Black High Definition Acrylate are recommended for fine detail and smooth surfaces. Of the two types of Frosted Detail plastic, "Frosted Extreme Detail" (FXD) prints in thinner layers producing much better detail and dramatically smoother surfaces. For Radio Control models, where durability and strength are important, some larger scale products are available in Strong and Flexible plastic (S&F), a kind of tough nylon.
Glue: cyanoacrylate (CA) "superglue" works best. Testors liquid or tube cement won't work. Testors cement works best for polystyrene plastic but these 3D-printed parts are either acrylic plastic or nylon.
Cleaning your parts: during the 3D printing process, a waxy substance is used to support certain part features. Although the parts are cleaned by Shapeways afterwards, some waxy residue may remain. It can be safely removed with mineral oil, or water together with a mild water-based detergent like "Dawn" or "Fairy" dishwashing liquid, baby shampoo (no conditioner), or "Simple Green" using an old, soft toothbrush, Q-tips or pipe cleaners. Do NOT use any cleaner, primer, paint or thinner containing acetone, acetate or methyl ethyl ketone (MEK).
Curing the plastic and smoothing surfaces: For products printed in "Frosted Detail" acrylic plastic and "Black High Definition Acrylate" plastic, during printing process, liquid resin is cured by ultraviolet light. Microscopic bits of resin may remain uncured. Let your parts sit in direct sunlight or under a UV or fluorescent lamp for a few hours to fully cure the resin. After your parts have fully cured, if desired, careful use of an inexpensive "air eraser" emitting common household baking soda can help smooth surfaces and remove any unwanted "frost" without harming detail. Air erasers, like an airbrush but much cheaper, can be found on Amazon.com. Models by Harbor Freight and Paasche are popular.
For those few products printed in "Strong and Flexible" plastic, a kind of nylon that is difficult to smooth, apply thin layers of primer meant for nylon, allow the primer to harden, then smooth the hardened primer.
Primer and painting:
For "Frosted Detail" acrylic plastic and "Back High Definition Acrylate" plastic, only acrylic primer and acrylic paints meant for plastic are recommended. Enamel paint may not harden on "Frosted Detail" plastic.
For "Strong and Flexible" products, only primers and paints intended specifically for use on nylon should be used. Other hobby paints may not adhere. Simply Google "primer for nylon" and "paint for nylon" for several good choices.
Do NOT use any thinner containing acetone, acetate, or methyl ethyl ketone (MEK). Acetone will attack acrylic plastic and damage it. Acetate is found in acetone-free nail polish remover. Acetate and MEK can cause a crystalline powder to form on the surface, even after painting, which is an annoyance to remove. The following chemicals may cause crazing, cracking, discoloration, or dissolving of Frosted Detail acrylic plastics: Acetic Acid, Acetate, Acetone, Ammonia, Aromatic Solvents, Benzene, Brake Fluid, Butyl Alcohol, Chlorinated Solvents, Disinfectant, Ethyl Alcohol, Kerosene, Lacquer Thinner, Lestoil® Cleaner, Lysol® Spray, Methyl Ethyl Ketone, Naphtha, Pinesol® Cleaner, Sulfuric Acid, Turpentine, Toluene, White Cap® Cleaner, and Xylene.