This tutorial will tell you how to paint, in order to add color to the Shapeways  White, Strong & Flexible material.

Our White, Strong & Flexible material is made by the SLS(Selective Laser Sintering) process on an EOS Formiga P 100 3D printer. The official name of the material itself is Fine Polyamide PA 2200. The material is a nylon(polyamide 12).

The material has a powdery feel to it because it a nylon powder(polyamide 12) that is sintered by a laser.

When painting:

• always have a clean and clear surface in front of you
• always use a well ventilated room
• always read the safety labels on the materials that you buy.
• this tutorial is only intended for adults
• clean your part with a cloth to remove any residue

There are several types of paint that you can use to paint White, Strong & Flexible

• acrylic paint, water based
• acrylic paint, solvent based
• cellulose spray paint, solvent based
• nail varnish, acetate solvent based or acrylic
• oil paint

currently we have one tutorial that will deal with acrylic paints

Acrylic paint is one of the most common paint types. We have found that the best results occur when you use modeling paints. We liked the Tamiya Color Acrylic paints  and were particularly impressed with the Revell Aqua Color line.

We tested both solvent and water based acrylics and could generally not find a noticeable difference in performance. Solvent based acrylics are flammable though, worse for your health and worse for the environment so avoid them if you can.

• We suggest that you find a clean good table to paint on. Remove all the stuff from the table and cover it with something.
• I personally hate newspapers because the ink seems to get all over me in the end. Trash bags, regular paper, old magazines and old cardboard boxes torn open and folded flat work well.
• Get at a old mug, cup, disposable cup or old ceramic bowl and fill it with water. You can use this to clean your brushes. This item should be expendable.
• Do not wear too nice of an outfit.
• There are a myriad of brushes and brush types try think about the level of detail you need when buying and buy multiple brushes.

• Acrylic paint is easy to was off your hands with warm water and detergent.
• Once acrylic paint has dried on or “into” something it is very difficult to remove from your: 3D printed model or anything else for that matter.
• Painting your Selective Laser Sintered model will change its texture. The powdery finish will feel much smoother after two coats have been applied. You might like this but you might miss it also.
• If your model has a base or another part to it that will remain from view when you eventually display it then you can test the paint on this portion of your model.
• Painting a character that has a base and is upright is very straightforward. Another object however,  where you want to paint each and every side requires planning and patience. At one point you will have to lay the model down on a painted surface. Wait for this surface to completely dry before doing this.
• You could dilute the paint with water.
• Acrylic paint is sticky and if your model is wet it will stick to other surfaces. 
• Paint almost always looks better when wet then when it is finally dry.
• Speed kills. Try to take your time and be patient.

White, Strong & Flexible(SLS, Nylon 12, polyamide 12 etc.)is a porous material made from a powder that is sintered by a laser. 

Because of this the material “sucks in” paint. Thin layers of your model are easily penetrated by paint. 

The model below shows a 2mm thick part painted on one side.

If you flip the part you can see that the paint seeps through the model and enters into it.

Please take this into consideration when you only want to paint one side of a relatively thin part or if you would like to make the other side a different color. The penetration depends on the amount of paint you use. Less paint equals less seepage. It should not go more than a few millimeters deep but this would depend on how thickly you lather on your paint.

If we look again at the previous model we can also see what happens if we for a small portion of it do not paint in the same direction as we have for the rest of the model.

You see the lighter portion on the top of the first "e" , ugly right?

If you use too much paint on your brush when painting or simply apply too much paint to the model in general per coat the paint will collect on the surface and make your model look yucky.

See this orange model for a chilling example.

And do you see the little silver specs? That is what happens when you do not clean your brushes properly in between switching colors. We were using metallic paint on the brush previously. We make these mistakes so you do not have to.

• Start by mixing the paint well. Close the container if you are not using it and mix it again periodically.
• Acrylic paint dries quickly, this is a good thing but also means that the paint will dry on your brush and turn it into a useless gloopy mess. If you're not using your brush, remove the excess paint and keep the brush dry in your water cup.
• If you press your brush too hard you will ruin it.
• If you wet your brush and twist it lightly into a fine point you can get the best details with it.
• If you see the cup become cloudy then it is time to replace the water in it.
• Always replace the water when switching colors. 
• Do not use too much paint on your brush. When applying paint remove any globs of paint by pressing the brush against the rim of your paint container while retracting it.
• Brush in one direction only. Think about where you want to paint and where you're going next.
• Wash brush by twirling it in your water cup and squeezing it gently.
• When changing colors make sure that all the old paint is removed from the brush. A good way to test this is to run the brush over a small piece of cardboard or by pressing it against the bottom of your water cup.
• If you want to create straight edges between two colors you can mask one area using tape. First stick the tape to the table and then remove it so that it is not very sticky any more, this way you  are less likely to leave traces of the tape behind. Be very careful to remove any traces of glue from the model after removing the tape. Be sure not to stick the tape to wet parts of your model.  
• Apply one coat and then leave to completely dry then apply the second coat. We suggest that you always use at least two coats. The drying time differs depending on the paint you use. No primer is necessary.

A blue painted model:



We have a movie here that shows you the fun we had while painting.

We hope you enjoyed this tutorial. If you though it was oh so basic and have a lot more painting knowledge than we do then we would love for you to help us out with making an advanced painting tutorial, email joris (at) shapeways (dot) com. If you have Shapeways models that you have painted we would love to see them! Post them on the forum or mail them to us.