Creating a Stencil
These instructions describe how to create a stencil using methods available at Makespace -- cut paper and cut sticky vinyl.
- Choose the method best suited to your design based on the characteristics and limitations of each method listed below.
- Choose paper (lasercut or handcut) or cut sticky vinyl. Note: only people trained on the lasercutter can use it.
- Remember to pay for any newsprint paper and/or sticky vinyl used
- Use newsprint paper. This is thin (50 gsm) and will cling to the screen when wetted with ink. Office paper (80 gsm) is too thick to cling and then wrinkles when wetted without contact with the screen to support it.
- Tape the paper to the underside of the screen using masking tape (stored in the small cabinet to the right of the print area).
Characteristics / limitations
- Suited to designs without 'islands' (for example the middle of a letter 'o')
- No manual 'weeding' or peeling required to transfer to screen. No masking off required.
- Design does not need to be reversed.
Sticky vinyl stencils
Characteristics / limitations
- Can support stencils with 'islands' but note that larger lettering and designs work better than more detailed ones.
- Reverse the design before cutting. We recommend that the stencil is stuck onto the underside of the screen, closest to the workpiece. This avoids the squeegee catching on pieces of the vinyl and peeling them away. Putting the stencil on the print side (underside) of the screen also gives a more precise print.
Lasercutting paper stencils
A lasercut stencil can make use of shapes or lettering created in the usual way (using Inkscape). Use a whole sheet of A2+ newsprint paper.
Recommended cutter settings: speed 64; power 15.
Many designs can be printed with flat colours.
It is also possible to create shaded colours, with some limitations. Screenprinting shaded colours uses the traditional technique of halftoning -- splitting an image into small dots or lines of varying sizes.
Creating halftones with Inkscape
- Import a bitmap
- Create a small filled circle (or other shape) at one corner of the bitmap
- Open Edit > Clone > Create Tiled Clones ...
- On the Trace tab select Trace the drawing under the tiles
- In section 3 Apply the value to the clones' select Size. (Unselect Colour and Opacity as these are not relevant to the result.) Presence controls whether lighter areas are filled with small dots or left blank, which is a choice which can be made for a particular design.
- Save your work at this point as Inkscape may crash attempting this process!
- Click Create
- Note that as this process is quite intensive for Inkscape it may take several minutes. More complex images may fail to complete. So it is advisable to remove background detail from photographs and use a dot size which does not give a large number of dots.
- When the halftone pattern looks as you want it, delete the bitmap image and export the image as DXF ready for cutting.