Guide to Digital Fabric Printing

This Guide to Digital Fabric Pritning was written by Solii Brodie – one of the directors at Be Fab Be Creative, a reactive digital fabric printing bureau, printing on a range of cotton, linen, silk and bamboo - specialising in small, bespoke orders.

What is Digital Fabric Printing?

To put it simply, digital fabric printing is the act of printing digital files on to fabric, with the printing part of the process working much like your desktop inkjet printer. Only, think bigger and where the printing element is only one part of a larger process.

There are a number of different types of Digital Fabric Printing Ink Technologies. Each works on specific fabric types and being best suited to particular purposes and offering varying qualities of print. The type of fabric printing will also dictate both the price and longevity of your printed design.

A simple demonstration of this is the difference between a T-shirt that has a waxy quality to the print design, where the print effectively sits on top of the fabric compared to those where you can feel no difference in the fabric whether it’s printed on or not, and variations in between these.

This diagram demonstrates the 4 basic ink technologies/chemistry's and the fabrics that they are able to print on. For the purposes of this post we are going to discuss Reactive Dye Digital Fabric Printing as this is what we work with at BeFab Be Creative.

Reactive Dye Digital Printing is the most versatile of the high end digital printing technologies, with its ability to print onto both silks and plant based materials (eg cotton, linen and bamboo) and where the print has no effect on the handle of the fabric as the dye bonds directly with the fabric fibres. This also means that reactive printing has a greater light and rub fastness than other print technologies making it perfect for apparel and home ware.

What do you need to know before you’re ready to print?

Colour:  Have fun with your design, you can print as many colours as you like when using digital printing. It’s designed so that you can achieve photo quality detail so there should be no restriction on the colours you use, just have fun!

Fabrics: We will rarely recommend a fabric to use, when it comes to most projects the selection of fabric is largely a matter of taste. We recommend you order a fabric sample book so that you can see and feel the handle of the fabric and also get an idea of how a comparable print looks on each material. For instance, we have designers who are printing silk scarves on every one of our silk options; similarly all of our cottons and linens have been used for garments or curtains, and the thicker options for home ware so it really is entirely up to you and the end result you want to achieve, as well as considering your cost and margins.

Cost: At BeFab we like to keep things simple so we have a simple price per meter with no added extras. Though bear in mind, many printers work on a Print + Fabric + Admin/file set up/additional print length etc = Total cost per meter, so the end cost it is not always obvious at first or as transparent.

File standards: as a rule these should be RGB, between 150 – 300 DPI , and saved as Jpegs at the correct scale and orientation you wish it to be printed.

File orientation: the fabric runs down the height of your file so the cut edges are top and bottom and the fabric salvage runs down the sides.

Repeat patterns: we recommend you only upload the minimum repeat tile if the design/repeat is seamless at your end, it will be at ours!

Placement prints: When the design is either made up of different elements or needs to be printed in a particular layout, lay your files as you want them printed, and keep seam allowances in mind. If you require white space at either end make sure you mark the boundaries at the start and end point of your file so we know where to cut the fabric where this may not otherwise be obvious.

File layout: If you are printing a number of squares of different designs, although digital printing is designed with multiple colours in mind, think logically where possible, if you have 3 light designs and 6 black ones lay these out so that lights are all together in a row and the blacks are together rather than mixing them all up. You wouldn’t put a red top in with your whites and the same logic is true where possible in the digital possessing and will potentially speed up production, if not possible then that’s fine.

Sample: We cannot stress to you enough the importance of sampling. It is important for many reasons, every printer is calibrated differently, we have calibrated our printer so that it matches the Uncoated Pantones as closely as possible, so this is always a good place to start. However your design will look different on your screen as it is backlit as opposed to being on a matte or sheer fabric. We offer a sample service that is 20cm by ½ the width of the fabric which we then print twice, side by side, which means we both keep a reference for any future prints for accuracy. You can get a lot into this size of print, so play with different saturations and always work to the same scale and design that your print will be rather than isolating colour chips or scaling down a design as this can affect your perception of colour.      

 And if after that you have questions just ask, we’ll always be happy to help you.

How does the print process work?

Unlike with traditional screen printing where the thick ink ‘fixer’ is incorporated into the ink itself, with digitally printing this fixer would clog up a printers ink heads, so the fixer must be applied to the fabric before it is printed. This is referred to as the ‘padding’ or pre-treatment.  This is done by an external fabric finisher (which sounds confusing when in digital print terms this is the first part of the process!)

Each new pre-treated fabric is then print tested and the printer is calibrated to the amount of ink that fabric can hold to achieve a crisp, bright print. Too much ink and a print will not be crisp, too little and the colour accuracy/brightness may be lost. The average shrinkage is calculated and then the fabric is given a ‘profile’ which the printer uses each time it prints this particular fabric.

Now for printing your design! Your fabric is placed on the printer, the ink head is set to the correct height for the fabric, there is only a few millimetre clearance over the fabric so the height for a silk will be quite different to that of a upholstery weight linen. This head height is important not least to protect the ink heads but it also affects the crispness of the printing.

This is the bit where we look a like a cat watching the tennis, as we watch your print emerge as the print head passes right to left and back again across the fabric, laying the ink on the fabric in layers over a number of passes.  

This is the most vulnerable time for the fabric as the print has not yet been ‘fixed’. In order to fix the fabric it must be steamed so that the printed ink can bond to the fibres of the fabric. Each fabric requires a different length and quantity of steam depending on a number of variables including fabric type and length of print.

Once out of the steamer the fabric needs to be washed in order to remove any excess ink, further fix the print and wash out the excess fixer which has now done its job. The fabric is then dried and ironed along with our final quality control check.

Only at this stage do we know your fabric is ready to go, at which point it is packaged up and on its way to you.

Find out more about BeFab Be Creative here

You can also take a look at CAT Centre, a commercial digital fabric printer in Glasgow

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If you've enjoyed reading this Guide to Digital Fabric Printing read our Tips for Textile Production: Textile designers, Laura Spring on small-scale production and the outsourcing of larger batches in a small creative business.