After I graduated, I worked on a hotel site for a certain large three letter US news company. Now, back in those days, a website was just seen as an extension to brochure advertising. And for the majority, nothing has really changed in the intervening decade.

One of the first things I've noticed is that when working for a Blue Chip, there is a very strong disincentive against doing things the Right Way. This is because the clients will ask for what they think they want. This is usually not what they really want, and is pretty much always miles away from what they need.

And what companies generally start off thinking they want is something identical to their offline stuff.

For small companies with no web development budget, this is understandable. They paid for the development of the brochure, and placing it on the web on a cheap host will expand the scope of that investment for almost nothing. And heck, if they registered the domain name, they have to do something with it...

For Blue Chips, however, the problem is their in-house design department. These tend to be led by long-established graphic designers who've been working there 20 or 30 years, who know the company style handbook by heart: the Pantone colour numbers of the company colour scheme; the measurement in points of the required page gutter; font size and line spacing and how to balance them against line length; authorised reproduction sizes of the logo in inches; their citations comply to ISO 690 and ISO 832 (for style and abbreviations respectively); date, time, currency style; and so forth ad infinitum. The company font has been licensed from a font house at vast expense.

They then wish to apply these things to the web, treating the web the same as a print medium. All their training is in the arena of print, they have no knowledge of the limitations or extended abilities of the web, and they do not see the need to create a new style document for the web.

They then become upset when the web designer uses words like "impossible". But many things are truly impossible.

Colour.

Print designers are trained to use very precise colours. Colour is important to them. So they have a system called the "Pantone colours", which gives every colour a specific number, selected from an "RGB colour cube".

The designers are experienced and willing to work with the limitations of the colours in the print medium. Look at a shopping bad the next time you are in a supermarket. The stacks of bags (I noticed this in Sainsbury's) will have the logo MUCH darker than you are used to (Sainsbury's uses an orange logo - but the stacks of plastic shopping bags the logo looks like dark brown). This is because there are many layers of the logo one behind the other. Pull a bag off the pile, and on its own, it is the correct colour. That colour will have an exact Pantone colour.

Pantone colours are impossible to duplicate on a computer.

Monitors come in two main flavours: cathode-ray tube (CRT) monitors work, ultimately, on electron-intensities. Each "cathode ray" blasts electrons at a respective pixel: red, green or blue. The monitors allow an intensity from 1 (grey) to 255 (brightish) for each colour. With liquid crystal display (LCD) screens, each pixel instead is a little black filter, sitting in front of a coloured light which goes from 0 (block most of the light) to 255 (block none). Plasma, LED and other screens work in vaguely similar principles to one or the other.

So, if you put in the value, say, 100 red, 100 green, 0 blue, you will get something that's yellowish. How intense the yellowish appears to you, depends on the light shining on your monitor, your monitor's brightness setting (affecting how bright that value of 255 is), the contrast setting (affecting how far apart each of the different number values are), the individual brightness tuning values for r/g/b, whether you've degaussed it lately, the screen resolution, the "temperature" settings, how long the monitor has been on for...

You can, with sophisticated tuning equipment, "calibrate" a screen to approximate the values given by some standardised conversion table from Pantone to RGB. But when you hold up the printed copy and place it beside the screen, the colours will STILL not look the same. Because the printed copy is not glowing, and the monitor is. And no other monitor that your page is viewed on will ever look the same anyway.

Size.

And then there are sizes. Print designers are used to working in points, or inches, or centimetres. They say "I want this to be nine point text with a banner six inches wide". Then they look at it on the screen and say "that's only six inches, and that text is so small as to be unreadable! And on that other screen, it's too big!"

A web page knows nothing about the size of the screen it's being displayed on, nothing about the size of the browser window, nothing about the screen resolution. All it knows is how many pixels wide it is. How many pixels there are to the inch will vary with all these things, so a wild guess must be made. Again, the value of this wild guess can be calibrated so that your operating system is aware of how many pixels there are to the inch, but nobody does this. So your operating system makes an assumption: and different operating systems assume different numbers of pixels per inch. Obviously, this assumption changes depending on the screen resolution. When you select "10 pt" text in your word processor, you will see it displayed at a size according to this assumption (typically 1 pixel per point on the Mac, used by which most graphical designers: 1.2 pixels per point on the PC, which is used by most users browsing the web).

So, viewed at the same resolution, the items on your page will be half the size on a 14 inch screen than a 28 inch screen. This is intuitive to a regular computer user, but not to print designers, who are used to being able to specify exact dimensions.

Well, what about proportions, then? Can you assume that something 10 pixels by 10 pixels is a perfect square? No. Because again, the dimensions of the screen can be fiddled by the settings on the monitor. You can make it shorter. Wider. My video card allows me to select many resolutions: two are 1280x1024 and 1280x960. If I change between them, both take up my full screen: but clearly, in the latter, the pixels must each be taller.

Can you even assume a straight, horizontal line? Definitely not. Cathode ray monitors have have convex display surfaces, and "Barrel", "Pinch" and "rotation" settings, which will cause lines to bend and rotate. Projectors may be projecting onto a screen at an angle (you all remember that from school/university lectures, right?) For this, they have "keystone" correction, but it's rarely perfect.

So... That covers the ability of the hardware: you can't truly believe anything about it, since you have no control over the monitor, nor the operating system that people will use to view your web page.

So far, it's stuff that most designers, once it's explained to them, will be able to understand. They'll be happy with "nearest approximations". They'll be happy, instead of having a font or graphic size that is a precise dimension, to have one that's visible to the majority of people.

Next time, I'll cover the software limitations. This is where the real stumbling blocks come in, because, well, you should be able to make a computer behave however you want... shouldn't you?