A vinyl job from file to wall

What the machine is

A cutting plotter holds a small blade in a swivelling holder and drags it over material on a roll while the roll moves back and forth under it. It does not print. It cuts outlines, and the colour comes from the vinyl you loaded.

Roland and Graphtec are the machines most signage shops aspire to; a large number of small shops run cheaper Chinese plotters with ArtCut, SignMaster or FlexiSign. Cricut and Silhouette are the hobby end of exactly the same technology.

The materials, because they decide the design

• Cast vinyl: thin, conformable, 5 to 10 year outdoor life. For vehicles and curved surfaces. Expensive.
• Calendered vinyl: thicker, cheaper, 3 to 5 years, shrinks a little over time. Flat surfaces: shop boards, shutters, windows.
• Reflective: for road and safety signage. Thick and hard to weed.
• Heat transfer vinyl (HTV): cut, weeded, then heat-pressed onto fabric. Must be cut mirrored, because it is applied face down.
• Etch or frosted film, one-way vision perforated film for vehicle windows, floor graphics with a textured laminate.

Preparing the file

Five steps, in this order, and skipping one costs a sheet of vinyl:

1. Convert all text to curves. The shop’s software will not have your font.
2. Convert all strokes to outlines. The blade follows the path. A stroked letter is cut as a single line down the middle of the outline, which is the commonest beginner failure.
3. Weld all overlaps. Two overlapping script letters are two closed paths, so the blade cuts the buried edges too and the join falls apart. Union everything that visually touches.
4. Remove everything invisible. Stray points, zero-length paths, objects outside the artboard, hidden layers. The plotter cuts what is in the file, not what is on screen.
5. Set the real size. Build at 1:1 if the software allows. Put the size in the filename.

Then check the node count and simplify any traced artwork. The plotter decelerates at every node; a 4,000-node letter takes minutes instead of seconds and comes out rougher.

Weeding sets the minimum feature size

After cutting, a person picks out the waste vinyl by hand with a hooked tool. This is weeding, and it is where design meets physical reality.

• Anything narrower than about 2 mm tears while being weeded.
• Fine serifs, thin script connectors and small counters are not a stylistic risk, they are physically impossible.
• The counter of an a or the middle of an o comes out as a separate piece, held in place only by the transfer tape. Below about 5 mm across, they get lost.
• A design with hundreds of small holes takes an hour to weed, and that hour is on the quotation.

For a complex job, add weed lines (extra cut lines through the waste, dividing it into manageable sections) and weed boxes around groups of letters.

Application

Worth understanding even if somebody else does it, because it changes the file.

1. Cut, then weed.
2. Lay application tape (a low-tack transfer paper) over the design and squeegee it down.
3. Peel the design away from its backing; it comes up on the tape.
4. Position on the surface: wet application with soapy water gives you repositioning time on large pieces.
5. Squeegee from the centre out, then peel the tape back at a sharp angle.

Which is why the counters matter: the tape holds them, and the design must keep them large enough to survive.

The free path

• Inkscape exports SVG and DXF; most cutting software imports both. Set the document to millimetres at 1:1.
• Inkcut, a free Inkscape extension, drives many plotters directly over USB or serial, handling HPGL output and weed boxes.
• LibreCut and vpype are other free options for plotter workflow.
• Hobby machines (Cricut, Silhouette) mostly need their own software, which will import SVG.

The question to ask before you draw

What is the smallest stroke you can weed in this material, and what is the sheet width?

Sheet width decides whether a 1.4 m sign is one piece or three with a join, and the smallest weedable stroke decides your typeface. Both are one sentence, and both change the design.