Good labeling is important in creating a finished, professional appearance for a project.  There are many options with different levels of difficulty and different standards of finish.  In this article a few of those options will be explored.

3D printing

Adding text to the surface of a 3D print is relatively easy (depending on the CAD/CAM software) and is very suitable for some projects.   Generally, the label has to use large lettering in order to print correctly, and that means it is only suitable for small amounts of text, such as "On-Off"  or "+5V".  As the labels are created using CAD any text and graphic is available. 

When labels are created standing out from the surface they can be highlighted by painting the raised surface; when they are created as indents there are techniques for masking the surface and painting the indent.

One problem with this approach can occur where labels are printed on the top of the case.  The part is usually printed with with the top on the baseplate in order to minimize supports and infill.  If labels are printed as raised text then the surface on the base is no longer flat, and if printed as an indent then it is hard to get a sharp edge on the bottom layer, due to 'elephant's foot'.  A face that is a single sheet, so it is printed with the back side on the baseplate, overcomes this problem.

Dual-filament 3D printers can be set up to include a label of a different colour embedded into a flat surface.  Results are variable, depending on the printer and the filament used.  


Printed labels

Plotters and printers can share the same print material.   This can be any style of printer paper, from plain bond to high gloss photo paper.  If plain bond is used it should be finished with a clear coating.  High-gloss photo paper is very suitable for labels, and is available either as plain sheets (often in 10x8cm photo format) or as self-adhesive A4 sheets.  When used with a plotter some testing for the most suitable type of pen is worthwhile, as some inks will take a long time to dry and some might never dry properly.

A wide variety of printing material is available for both printers and plotters, ranging from standard bond to light card, various types of gloss or photo-quality paper, self adhesive media, and special material such as transparent film.  Care must be taken to ensure anything other than bond is compatible with a laser printer, and self-adhesive or high-gloss media might not be available for some lasers.

Inkjet and laser printers are inexpensive and readily available, but ink or toner may be expensive.  Graphics and text is limited only by the capability of the application that creates the image.  Resolution is good. 

Plotters are more expensive, unless they are home-made such as a conversion of a 3D printer or CNC machine.  The advantage of using a plotter is that the pens are cheap and different pens can be used for different effects, such as very glossy high-build.   Resolution depends on the pens that are used, and plotters do not handle solid areas well.  It is difficult (or expensive) to use more than one colour in a label, but plotters tend to use less material because it is possible to cut out any size label and use the rest of the sheet next time, whereas printers often require a standard size sheet. Examples shown here were created with a plotter.  Preparation of images to print is slightly more complicated with a plotter because everything must be reduced to a line drawing.



Desktop label printer

Dedicated desktop label printers are available, but they are expensive and often the choice of print material is limited.  They are mainly designed for high volume applications, and sometime use a proprietary protocol that may restrict text and graphics options.


Hand-held Tape Labeller

Hand-held tape label printers are available and some are quite inexpensive.  They typically use a temperature sensitive plastic tape which is available in a variety of different base colours (including transparent), and a similar range of print colours.  As the colour is determined by the tape only one colour can be used for any one label.  There will be a limited number of font styles and sizes available, and graphics will only be available as icons.  In some cases custom icons can be loaded into the labeller.

The hand-held labellers are very easy to use, but quite hard on batteries - an adapter is recommended.  The manufacturer's recommended adapter can cost several times the price of the labeller: a generic adapter is much cheaper, but it must have the correct specifications (including plug polarity) and sometimes the details can be hard to find.  For occasional use rechargeable batteries are suitable.

Tapes are available from many sources and prices are reasonable.  The printing is clear and sharp and resists chemicals and abrasion well.  The glue used for the tape is usually very effective. Tape labellers are very useful for creating labels for wrapping around cables - something that the other forms of labellers cannot do easily.