On drawing in scale for print

Hello all, happy new year! (Is it too late to say that? It’s mid-January. It’s probably too late to say that.)

An interesting question this morning from one Rik Jackson on the topic of drawing to scale. It’s actually a very useful question, the answer to which is relevant to artists when they’re beginning the process of sketching, so with Rik’s kind permission I’m doing a blog post on it. That blog post is this blog post – how exciting.

Rik’s question went a bit like this:

I want to make sure I produce my art at the correct dimensions. I usually work in A3 – I wondered if you are able to advise me on equivalent page sizes, so that I can mark out an American standard page dimension within an A3 page?

This makes sense. Most art supply stores will sell paper in the standard “A” sizes, and those don’t scale perfectly into either the US Standard or the UK Standard (if you scale A4 down by height the US Standard goes to 260x184mm – 14mm wider than desired – and the UK Standard goes to 240x170mm – 13mm wider than desired). Rik needs to know the dimensions to mark out as the working area on his A3 sheet.

If printing between A5 and A4 treat it like it’s A4

This works for both the US and UK Standards (which are the most popular sizes). The dimensions we’re working with are:

A5: 210x148mm Trim Size, 216x154mm Bleed Size
UK Standard: 240x157mm Trim Size, 246x163mm Bleed Size
US Standard: 260x170mm Trim Size, 266x176mm Bleed Size
A4: 297x210mm Trim Size, 303x216mm Bleed Size

Both the target sizes fall between A5 and A4, so they both require an A4 slot on the print sheet. If you’re drawing at life size on an A4 sheet of paper this is simple – mark out the bleed and trim areas for your target size and make sure you stay inside the lines. But for many artists A4 is a bit fiddly & small to work with – you’re more likely to want to work to A3 and scale down to A4. You need, therefore, to know the conversion between A4 and A3 to make sure you’re drawing in scale…

A3 is ~141% of A4 (and A4 is ~141% of A5 and so forth). Take the dimensions of your target size and multiply them by 1.41 to get the dimensions of your working area.

So if Rik’s working on an A3 sheet and he wants to mark out the bleed and trim areas for printing to the US Standard he needs to do the following:

Bleed height: 266 x 1.41 = 375.06mm
Bleed width: 176 x 1.41 = 248.16mm

Trim height: 260 x 1.41 = 366.6mm
Trim width: 170 x 1.41 = 239.7mm

Safe area height: 254 x 1.41 = 358.14mm
Safe area width: 164 x 1.41 = 231.24mm

So mark those areas out on your A3 sheet (rounding to the nearest millimetre unless you have a very fancy ruler and a very steady hand) and either trim away the waste or mentally discard it. Now you’re drawing in scale for your target size, so as long as you don’t fiddle with anything when scanning you can be sure that you’ve got the right aspect ratio for printing.

As long as you’re working with a sheet of paper in the “A” sizes this multiplication will work for any target size, not just the UK and US standards. These won’t give you 100% exact 3mm bleeds, but it’ll get you close enough that we should be able do the rest. If in doubt when sizing round whatever you get for the bleed UP to the nearest millimetre and whatever you get for the trim DOWN.

Drawing on A3 to A4 with bleeds

OK, so you’ve got your piece of A3, which is 420x297mm. That’s a good start. You want to use the whole sheet, because you paid for that sheet, darn it, but you want to make sure you’re leaving the correct bleeds for your A4 comic because you love your printer and don’t want them to be sad. This is a little more complex to work out – you can’t really do it precisely. Well, I can’t really do it precisely. I’m sure that someone good at maths could, but that’s not the situation we’re confronted with. We’ll do it close enough for government work.

OK, so the reason that this is annoying is that A3 is ~137.5% of A4 +3mm bleeds widthways and ~138.5% of A4 + 3mm bleeds in height. Super helpful. It’s probably easier just to give you the box sizes for the trim area.

Trim size (drawing A3, printing A4): 412x289mm
Trim size (drawing A3, printing A5): 408x285mm
Trim size (drawing A4, printing A5): 289x202mm

Mark out the relevant size on your A3/A4 sheet and you’ll be leaving pretty much enough bleed when we scale the artwork down. None of these transformations are perfect (although the US & UK Standard ones are pretty damned close) but they’re all *significantly* better than nothing!

General bleeds reminder

A detailed discussion of bleeds can be found here, and 1:1 templates are over on this here page. Those are definitely worth a look when you’re prepping the artwork to go into print.

As we’ve been talking about bleeds, though, it’s worth taking a moment to refresh your memory on the most important points about them:

• If something reaches the trimline it must reach the edge of the bleed area as well. Whether you’re working 1:1 off the templates, or working off an A3 sheet to draw to US standard scale, or working off an A4 sheet to make A5 scales with bleed; this fact remains true – it needs to bleed. Honestly, this isn’t just me being picky (I’m not picky, just ask [404 – joke not found]), this is actually crucial. Without a bleed your artwork can’t be registered on a press, which means either you’re risking white borders from mis-trimming, or you’re risking us adding a false bleed using photoshop’s clone tool, which may appear in print. You don’t want either of those – they look *awful*.
• Unless your artwork is bordered by a solid block of colour a solid block of colour is not a bleed. Which sounds obvious, but you’d be surprised… (In fairness, it’s more commercial clients than comickers that get this wrong.)
• If you’re finding something hard to grapple with, or don’t understand some of the terms or concepts, get in touch with your chosen printer and ask them for help!

Thanks again to Rik for the question that suggested this post.