Creating labels for curved surfaces

[Xhris]

Hi everyone,

I came across a challenge this morning that I solved and thought people here could benefit from my work. The task was to create a label to put around a cup. Unfortunately the cup was conical in shape which made designing a label more difficult than creating a rectangular strip.

Fortunately the conical cup was rotationally invariant but I realised I’d need to do some mathematics to solve the problem. I considered producing a full walkthrough of the geometric calculations and logic but then decided it was inappropriate for TG and have instead just made a mini-tutorial with the essentials needed to complete the task for simplicity and ease of understanding.

(See figure below). Essentially, you just have to measure the top and bottom circumference of the cup and its height. Then stick the numbers into the equations in the attached xar file and get values of the two radii of curvature and angle between the arcs swept out (making sure you convert to degrees from radians). These last three parameters allow you to draw a scale diagram in Xara to get the arc area region needed. Once you’ve designed the surface logo about a rectangle of similar dimensions to the arc region, you can use the Mould tool to map it accordingly. Any bitmaps may need to be traced to be correctly moulded.

Hope people find it useful at some point.

Xhris

[Scotty]

Hi,
Great work and thanks for the formula.
Jim

[jeffb]

Great formula but need to measure and work out, have a look at attached file, looks a bit complected but is quite simple, have tried to get it layed out on a single sheet, just mark out and draw, not to good with the maths so with trianglation not needed.
Have a good day all

[Xhris]

Hi jeffb, I didn't quite follow your instructions; I think this kind of thing is best shown in a video. Edit: Oh wait, now I think I get the basics of it. Does this really work for all cup sizes?

You did make me realise that some people may struggle a bit with the maths, so I wrote a replacement tutorial with an example of how to solve the equations step-by-step. Hope it makes things easier for people.

Xhris

[jeffb]

OK Xhris
Believe me this will work for anything, I was doing this after 5year apprentaship 40 years or so ago, have used it from small to big and when I say big would a ships funnel do!!
Yes the basic isvery sound practice and just needs adapting for other things, but as I say the basics are long proved

[covoxer]

Jeffb, your method is approximate. It is not precise. In your illustration it's quite clearly visible that the perimeter of the wide end of the cup is longer than the long side of your label.
Although all other dimensions are correct (curvature of the label sides and width).

[wizard509]

Hi jeffb, I didn't quite follow your instructions; I think this kind of thing is best shown in a video. Edit: Oh wait, now I think I get the basics of it. Does this really work for all cup sizes?

You did make me realise that some people may struggle a bit with the maths, so I wrote a replacement tutorial with an example of how to solve the equations step-by-step. Hope it makes things easier for people.

Xhris

Hi Xhris good to hear from you, your link does not work at least it didn't for me. Do you still your great website with the tutorials? Hope so, I thought they were both helpful and amazing.

[amybbehrens]

Good evening,
I am hoping to access both sets of instructions provided in this forum, however I cannot access this file type .xar.

Any advice or assistance is greatly appreciated.

[Egg Bramhill]

Hi Amy and welcome to Talk Graphics. This thread is over two years old and it'd need a lot of wading through for any member:

to access both sets of instructions provided in this forum

I believe what you are asking is how to open a .xar file. It is the native file type (along with .web) for Xara software. You can download a months fully functioning free trial at:

LINK

[kaylatmiller]

i can not open the file

Hi everyone,

I came across a challenge this morning that I solved and thought people here could benefit from my work. The task was to create a label to put around a cup. Unfortunately the cup was conical in shape which made designing a label more difficult than creating a rectangular strip.

Fortunately the conical cup was rotationally invariant but I realised I’d need to do some mathematics to solve the problem. I considered producing a full walkthrough of the geometric calculations and logic but then decided it was inappropriate for TG and have instead just made a mini-tutorial with the essentials needed to complete the task for simplicity and ease of understanding.

(See figure below). Essentially, you just have to measure the top and bottom circumference of the cup and its height. Then stick the numbers into the equations in the attached xar file and get values of the two radii of curvature and angle between the arcs swept out (making sure you convert to degrees from radians). These last three parameters allow you to draw a scale diagram in Xara to get the arc area region needed. Once you’ve designed the surface logo about a rectangle of similar dimensions to the arc region, you can use the Mould tool to map it accordingly. Any bitmaps may need to be traced to be correctly moulded.

Hope people find it useful at some point.

Xhris