Rotary cutting Part 7

Having done the 60 degree triangles and diamonds last time we probably ought to look at 45 degree diamonds – these are the ones used in 8-pointed and Lone Stars.

eight pointed starLone StarAs for the 60 degree diamonds – first cut a strip the width of the diamond plus 1/2 inch for seam allowance. Then trim the ends of the strip to 45 degrees using the 45 degree line on the ruler. Keep the strip folded in two as you will need half your diamonds cut left to right and half right to left – keeping the strip folded cuts these two at the same time without you having to worry about it. If using two colours for your diamonds. open the strips out and place them right (or wrong) sides together and then cut.

trim to 45 degsend trimmedNow line the 45 degree line up along one long edge, measure the same width as the strip along to cut the diamond. These are 2 + 1/2 inch diamonds.

measure diamondand cut the first diamond

cut diamondJust as before, slide the ruler along to cut more diamonds.

continueYou will need 8 (obviously) for an 8-pointed star – as you are cutting two at a time you only need to cut four pairs. Each cut pair makes a unit –

use for Lone StarAnd that’s it. Next time we’ll look at cutting the triangles you need for the unit often known as Peaky and Spike.

unit

 

 

 

 

Rotary cutting Part 6

Those lines marked with numbers that go across your ruler are for cutting 60 degree (or 30 degree) angles – especially equilateral (60 degree) triangles and diamonds. These are used to make hexagon shapes.

All rulers have these lines – some have more than others and some are clearer than others.

rulers and degree linesFirst cut your strip. For equilateral triangles cut the strip 3/4 (three quarters) inch wider than the required height of the triangle. So if the finished size of the triangle is 3 inches, cut a 3 + 3/4 inch wide strip.

Trim one end of the strip to a 60 degree angle. Which end depends on whether you are right or left handed among other things – dance around the strip and cutting mat until you decide which end feels most comfortable. Find the 60 degree line on the ruler and place it on one of the long sides of the strip –

60 degree linethen trim off the unwanted triangle.

trim end to 60 degsNow turn the ruler so it faces the other way, place a 60 degree line on a long side of the strip and the edge of the ruler against the tip of the first cut. This can sometimes involve a lot of dancing round the mat and turning the ruler over and round, but eventually you will find the right edges to line up (and it is much easier in the privacy of your own home than in a classroom full of students – or ‘sewing in public’ as one of our students described the feeling).

cut triangleCut along the ruler to cut the first triangle.

60 deg triangleTo cut the next triangle you need to dance around the mat again to line the 60 degree line up with one edge of the strip and the ruler going the other way to meet the tip of the triangle you just cut –

cut second triangleContinue dancing and cutting until you have the right number of triangles. You can keep the strip folded and cut two at a time for speed – the shapes are symmetrical.

Diamonds involve slightly less dancing! Thiis time add 1/2 inch to the width of the strip for a seam allowance – for a 2 inch wide diamond, cut a 2 + 1/2 inch wide strip. Trim the end of the strip as before.

trim end to 60 degsNow place the ruler with the 60 degree line along one long edge and the 2 + 1/2 inch line (or the same measurement as your width of strip) along the edge you just cut. You can cut this way –

measure diamondor this way –

measure diamond bYou end up with the same size and shape diamond.

diamond cutJust keep sliding the ruler along the strip to cut more diamonds. Once again you can keep the strip folded and cut two at a time. These diamonds are used in blocks such as ‘Tumbling Blocks’.

 

 

 

 

 

 

 

 

 

Rotary cutting Part 5

Once you can cut strips and then squares, cutting right-angled triangles is easy. Let’s look at ‘half-square’ triangles first. As you might expect by the name they are cut from a square by cutting it in half across the diagonal. The magic number to remember is 7/8 (seven eighths) as this is the seam allowance you need to add to the finished size of the unit. Standard seam allowance in patchwork is 1/4 inch so when cutting squares and rectangles we add 1/2 inch to the finished size of our squares and rectangles when cutting. With triangles we need to add a little more to take account of those pointy ends (technical term). So if your half-square triangle unit finishes at 3 inches once it is sewn into the quilt block then you need to cut the squares 3 + 7/8 inches. If you need to cut lots of these triangles (and you probably will) then first cut a strip that width. Then cut it into squares. Having cut the squares, keep them in their pairs (or fours) as they came from the strip – try not to move them too much. Place the ruler across the first pair from one corner to the other. If you wish you can use the 45 degree line on the ruler – put it against one side of the square – to be certain you are cutting an exact diagonal; but it is possible to get too obsessive about this degree of accuracy.

cut hstAs before, place the cutter on the mat against the edge of the ruler (make sure there is ruler above and below the line you wish to cut), remove the guard, roll the cutter against the edge of the ruler to the end of the square (and a little beyond) and replace the guard. Lift the cutter from the mat and gently check the cut has gone through all layers. If it hasn’t, don’t be tempted to go back and forth with the cutter until it is all cut through as you will only chew the fabric; likewise don’t tug at it to break that irritating thread that hasn’t cut as you will stretch this bias edge. Instead get a small pair of scissors and just snip the triangles apart where they are caught.

Now move onto the next set of squares and repeat until all squares are cut into two triangles.

cut second hst

cut hst done

Quarter-square triangles (or QSTs) are, as you might expect, a square cut in four across both diagonals. This time our magic number for the seam allowance is 1 + 1/4 (one and a quarter) inches. So if our finished quarter-square triangle unit is 3 inches we need to start with squares of 4 +1/4.

As for the HST units above, start by cutting a strip and then cut this into the right number of squares for your units. Once the squares are cut you can cut them into four. Don’t move them! Cut the first diagonal in the same way as for HST units above. Then, without moving the squares (move yourself), place the ruler on the opposite diagonal and cut again. Repeat with all the squares you require.

cut qst first cut

cut qst second cut

cut qst doneYou will find some tutorials for quick-piecing these triangle units and links to easy blocks on the tutorials page of our sister blog Meadowside Designs.

Next time we will look at using the 60 and 30 degree lines on the ruler to cut diamonds and equilateral (60 degree) triangles.

 

 

Rotary cutting Part 4

Having cut some strips the next step is to cut those strips into shapes, starting with squares and rectangles.

From that two and a half strip we cut last time we can cut two and a half inch squares or rectangles of various lengths – the most usual with that width being four and a half inches.

First trim the selvage from the strip. Depending on how many squares or rectangles you want to cut it may be more economical (and certainly quicker) to leave the fabric strip folded in two, or even four.

With the bulk of the fabric to the hand you hold the ruler with, line a line of the ruler up with the cut edge of the strip. Trim off the selvage and ragged edge of the fat quarter or both selvages of the width of fabric (WoF) strip. If you left the WoF strip folded in four then you will cut through the centre fold as well. What you do with these trimmings is up to you – throw them away or save them for ‘leaders and enders’.

trim selvage atrim selvage bNow turn the mat around (or very carefully turn the strip) so the bulk of the fabric is to the hand you cut with. Use the ruler to measure a two and a half inch square and cut – remember to remove the guard only when cutting and replace it as soon as the cut is made. (You will often hear our students muttering “guard off; cut; guard on; guard off; cut; guard on . . .” as they work). Gently move the cut squares a little, measure again and cut the next set of squares. Keep going until you have all the squares you need, remember you will be cutting at least two squares each time.

cut square(you can see in the photo above the slight discrepancy in rulers – the strip was cut with one ruler and a different one is being used to cut the square).

squares cutRectangles are cut in the same way – just measure a longer length. If you need to cut a really long rectangle – longer than the width of the ruler – don’t forget you can turn the ruler round and measure along its length. For really big pieces you can use the mat for measuring.

cut rectangleYou can find a tutorial for using your strips and squares to make 4-patch and 9-patch units and also some instructions for blocks using these units on our sister blog Meadowside Designs.

Electric Quilt again

A quick reminder that we have posted new Electric Quilt doodles for August – and it’s only the 3rd of the month!  Chris is extremely busy over at C&B Towers, writing patterns, planning classes and generally being productive.  Barbara is somewhere in Spain trying to plan classes and write worksheets also, but not managing to be quite so productive (I didn’t know it was a competition – Chris).  Hope you are all enjoying lots of stitching time.

Rotary cutting Part 3

Most rotary cut shapes are cut from a strip so being able to cut straight accurate strips is a vital skill. Last week we got as far as finding and cutting a straight edge on our fabric and this week we will cut a strip (or two) from it.

Before you cut check that the edge is straight – something happens to fabric left out overnight and all those beautiful straight edges turn wavy and frayed, we blame the fabric imps.

Now turn the mat with the fabric on it so that the bulk of the fabric is now to the hand you cut with. You can turn the fabric but be very careful that you keep those straight edges together if you have yardage and, somehow, even with fat quarters, the mere act of picking it up seems to stretch it all out of shape.

Fold the fabric up again making sure those straight edges are aligned exactly (or as near as you can possible make it).

fold fabricDecide, work out, or look up the size of strip you need to cut. If it is two and a half inches (a very common measurement) then find that on your ruler. Place the ruler on the fabric so that the required measurement is against the straight cut edges. The fold of the fabric should be towards you.

cut stripHold the ruler firmly, fingers out of the way!

photo6 hand positionPlace the cutter on the mat and remove the guard. With the blade snug against the ruler roll the cutter with a firm and even pressure along the ruler to cut the strip. You will be going through two or four layers but with a sharp blade this shouldn’t be a problem.

strips cutRemember you will cut more evenly, more surely and more accurately if you are standing in front of the ruler edge where you are cutting. Never be tempted to cut across yourself and never, never cut towards you – not only is it not very accurate (the ruler and fabric move and you can’t gain enough pressure) but the consequences of the blade slipping and cutting into you are potentially catastrophic.

You can download a handy list of Chris and Barbara’s Dos and Don’ts for rotary cutting here.

The instructions above are for using the ruler to measure and cut strips. This is the way Chris does it. Barbara uses the mat for measuring and the ruler as a straight edge guide for the cutter. Both methods are equally valid – whichever method you use however, be consistent as rulers and mats are slightly out of sync with each other (even different makes of ruler never quite line up exactly). There may be only microns of difference but over several seams those add up and decrease the accuracy of your piecing.

Next time – cutting some shapes from the strips.