Presented by Sarah Hughes, Head of Visual Impairment Services for South East Wales
Today we’re talking about tactile graphics. Tactile graphics are really important for blind users. Remember with tactile graphics it’s nothing at all to do with the way that they look it’s all about the way they feel. The way that those who are using tactile graphics will construct their understanding of them will be entirely opposite to the way that we look at diagrams as sighted users. Sighted users will construct their understanding of the diagram by looking at the whole picture and then honing in on the detail. Whereas visually impaired or blind users will do that entirely oppositely. They will look at the detail and develop an understanding of the diagram by putting the details together.
This is swell paper. You may also hear it referred to as Minolta or Zycem paper, these are trade names but it all amounts to the same thing. If you photocopy on to this rougher side of the page with carbon content that is above a certain level when you put it through a heat fuser machine it will raise anything that is dark so that you end up with a diagram that has a raised effect on the paper.
Choose the diagram that you prepared or you prepare your diagram electronically and select that diagram and when you are happy you need to just send it to your printer. Whether you’re using a photocopier or a printer, it is advisable that you only put one piece of swell paper through at a time. I’ve put the smooth side upwards and the rough side underneath. So I’m putting that in reverse into the printer as so. One sheet at a time to ensure that they don’t get stuck together. So I’ve just collected the diagram from the printer and as you can see, as yet, it’s not raised at all. So if I turn the machine on, making sure that the heat setting is not too high and not too low. I personally have it around 8.5. Having it too high will make the swell paper over bubble, particularly if the carbon content is quite greater at a particular point. As soon as the green lights on you know that the machine is ready. Each diagram is taken individually and fed through the heat fuser like this. When it comes out the other side each of the darkened areas of the diagram should now be swollen and you should have a textured effect that is sensitive to your touch.
If you’re producing your diagrams electronically it makes really good sense to make yourself a swatch chart. A swatch chart will give you the opportunity of feeling the different shadings that are available to you because quite often they can look very different but feel the same.
Here we have the diagram of a clown. There are three reasons why this is not a good example of a tactile graphic. Firstly the eye and the hair are too close together. Two objects that are distinct must feel distinct. The mouth has shading on it. It looks as if it’s there but to touch it doesn’t exist and the bow tie is very, very busy and these textures are very similar to touch. Remember what I said about your swatch chart.
Here we have a diagram of the heart. It’s very easy to put too many labels onto your diagram. So on this diagram we’ve just used simple letters to demonstrate each part of the diagram and those letters are fully labelled on the key that accompanies this diagram.
So alongside printing your materials off on a printer you can also produce your diagrams free hand using a special pen that is designed to be used with swell paper. I’ve drawn this flower directly on to the paper using this pen and this can be placed then into the swell paper heat fuser. I’ve added my own shading in there just to make the distinction between the leaves and the petals. One thing to remember is that if the line is too thick or the heat fuser is set too high you will get bubbling of the darkened parts of your diagram.
So I hope that’s given you an insight into the reason why we produce tactile graphics and why it’s so important to consider how they feel, not how they look.
The Tactile Library website (opens in new window) has a free library of diagrams used in education for pupils with visual impairment.
Get more tips by reading Making Tactile Diagrams