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.
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. However the usual technique of covering the area ans scraping away the surface will not work well with 3D printing, becasue the surface to be cleared is textured and retains the paint.
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 overcomes this problem. A single sheet can be inserted into slots in a base frame, or can be dropped onto supports on internal walls as a lid.
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.
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. Printing material is limited only be the availability of compatible pens.
A tip for printing small labels with special paper with printers: It is not necessary print the whole page for a small label using quality paper. The label can be positioned in the centre of a page, and a sample printed on plain paper, Then a small piece of the special paper (eg, high gloss or self-sticking label) can be carefully taped to the centre of the plain sheet, using the sample print to guide placement, and the label printed again.
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 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.
Hint: Some hand-held label printers are available at bargain prices. The reason may be that users quickly discover that usage with batteries is impractical and will purchase the power adapter, which costs many time the price of the labeller and is where the manufacturer makes their profit. The trick is to use a third-party generic adapter, but be very careful about voltage, current capability, and polarity at the connector. Labeller manufacturers tend to keep this information very secret, but it is available. Polarity at the connector may need to be discovered by investigating the internals of the device, because it appears common to make it the opposite to virtually every other device that could use the adapter.
